"Vietnam"-izing my MBK 1665GW

[silvio]

Hi guys,

Long time no post.

I'm in the middle of modding my 1665 GW to look as close as good as possible (aren't we all? ). I'm quite lucky to have owned a viet 1665 (pics link on my signature) and use that as comparison and a good friend's 1665 as reference point.

Last year I got my first MBK from TTK. At the comparison, the MBK is good but not as accurate as the viet-case, most notably are the lugs and their shapes: the right lugs - on the side where the CG is - is much fatter than the left one. This is the most notable flaw I first notice. Second flaw, is the uncorrect thickness of the bezel, on the viet the bezel is considerably thicker and very similar to the gen 1665 (we used a friend's 1665 as reference). Thirdly, is the non-working He Valve. But other than that, most features on the MBK is very good despite the fact to make it accept a 1570 movement we have to fabricate a custom movement seat.

To address this problem, I have an excellent lathe operator to work my case lightly, first is to evenly thin the right lugs and create "shoulders" - which is our term for rounded lugs edge, as commonly found on polished gen vintage Rollie. I also work on the CG outside and inside part.

Here is the pic after this light mod, sorry I don't have a frontal pic, but you can see your unmodded 1665 from the front and backside to check my point of the unbalanced lugs. Trust me, it'll look much better and closer to gen. Actually some gens have unbalanced lugs (mostly the right lugs are thinner than the left, but to discuss this would divide this forum in two and rollie's hell break loose ) >>

Shortly, mods done are:

1. Right lugs thinned out to even out with the left.

2. Rounded up edges

3. Clarks Superdome installed

To be done:

4. Retap tube hole, install gen tube & correct period triplock crown (thinner crown logo)

5. Enlarge lug holes to accept gen springbar

6. Gen insert

7. Flat top 3 datewheel (still no luck getting these, the gen silver datewheel won't fit 2836's. Appreciate your lead on this?)

8. Change movt to slow beat ETA

9. Gen endlink & bracelet

OR Option B - discard point 7 & 8 and fit a 1570 in?... very tentative

I'm lucky to be able to locate some gen parts to install, but holding it out until I'm finished and really sure with the case. Gen parts are cosiderably easier to install imho compared with getting the right case shape.

One feature that bugs me now is that the case-side which houses the tube (please see pics below to understand what I mean - the red marked area) protrudes too much beneath the bezel edge.

On the gen, when viewed frontal, it's concealed and should not stick out of the bezel edge. What's holding me to trim it out is this question:

* Trimming that area out makes the crown, thus the winding stem will sink deeper into the movement (keyless work). To avoid that we need to trim the outer side of the stem (that attaches to the crown) for about +/- 0.8 millimeter, which brings us to the big question: Is there a minimal stem length required for ETA2836-2? Would it be okay to trim out the outer part of the winding stem?

Understand that the MBK is based on gens, and the length of the case edge where the tube sits will fit the Rolex 1500 series movt's stem well, but I don't have any idea on how this will work on the 2836-2 stem length. On the logic, it should not pose any problem putting in mind that only very little part of the stem is removed, but then again I need to be sure not to ruin the good case before I move on. My watchmaker told me it's done all the time (the stem cut), but again I need any available input on this.

Is there any attempts ever done to modify this? Would value your knowledge on this very much.

I think it is an essential issue need to be dealt with, or it's just my over-anal geeky rep obsessive sick mind

Many thanks for looking guys.

[RWG Technical]

There is no minimal stem length on any watch. The threaded part of the stem on this model is quite long so you can trim it to your hearts content.

RG

[silvio]

The Zigmeister,

Many thanks for your reply. Highly appreciate your input on this!

I definitely feel much safer to continue work hearing from you.

There is no minimal stem length on any watch. The threaded part of the stem on this model is quite long so you can trim it to your hearts content.

RG

[silvio]

Here is a frontal pic I just took to prove my point on the elimination of fatter right lugs. As on the gen, the right lug area which seams to the CG should dissapear slightly behind the bezel, approx. to the outer edge of the '0' in the number '10' and '20' markers of the bezel insert. Please note that the distortion caused by the lens "hides" the protruding case/CG groove and sometimes varies the look.

I regret I don't have a pic of the watch before it's modded for comparison.

Please pardon my lack of photography skills.

[RWG Technical]

Your welcome. Looks like it's going to be one nice watch when your all finished.

There is quite a large amount of metal to remove from where the crown seats, I know how hard it is to cut these cases down, and cutting this large area, in between the CG's is going to be a real challenge. Using a file alone it will take hours, it takes me 2 hours to do the CG mod inner and outer, and I use a diamond cutting wheel.

Just make sure you have enough metal left over to secure the crown tube in the case

I wonder why this case looks like it does, I have seen many that have the crown in the correct position just below the bezel outer edge.

You may be better off to try and source one of these correct cases...

RG

[silvio]

There is quite a large amount of metal to remove from where the crown seats, I know how hard it is to cut these cases down, and cutting this large area, in between the CG's is going to be a real challenge. Using a file alone it will take hours, it takes me 2 hours to do the CG mod inner and outer, and I use a diamond cutting wheel.

That has crosses our mind several times and will pose huge challenge I understand. I just hope our nerve are steady enough to round up the inner part of the CG. It'll be flat after we trim that area and making a concave shape inside is not an easy job, but hopefully doable . Thanks for pointing this out, The Zigmeister.

Just make sure you have enough metal left over to secure the crown tube in the case

Definitely noted, need accurate measurements. But I notice the gen sometimes have some micro-millimeter still protrudes out, not very perfect either, so that definitely is a plus in mind.

I wonder why this case looks like it does, I have seen many that have the crown in the correct position just below the bezel outer edge.

You may be better off to try and source one of these correct cases...

RG

My theory is the uncorrect/flawed design is either "purposely" made, an intended mistake like "POLEX", etc or just a case of undetailed measurement, CNC scans gone bad... can't think of other explanation because the Vietnam case is just spot on.

Many thanks again for your inputs, The Zigmeister.

[freddy333]

Silvio -- Great start to your project. With the exception of the lugs (I have seen many vintage gen Dwellers with uneven lug widths), I have already done what you described in my MBW DRSD (including the addition of a working Hev)

(Close ups of Hev)

(CGs reshaped to match 1st version gen DRSD on double red sea dweller com)

(Another CG view of the DRSD sitting next to GMTIIC)

(New dial fit onto overhauled 1575)

(Test fitting new dial & 1575 into MBW case - 1575's locking screws fit into MBW case through cut-out installed for Hev mod)

(If you remove about .5mm of metal from the outside circumference of the 1575's date change ring (which comes off by removing the 3 circled screws), the movement will fit into the MBW case perfectly (Ziggy's mod))

[silvio]

Freddy,

Your is the best one I've seen here. Truly great work, you never know how hard it actually is until you've done it

Thanks for sharing the link on the He-valve rework, will be a good starting point to learn.

That through-cut you made looks quite similar to the viet's... kudos!

One question: would you recommend a Watchmeister datewheel for the best replacement, or any others? Is there anyway to source them nowadays?

[freddy333]

One question: would you recommend a Watchmeister datewheel for the best replacement, or any others? Is there anyway to source them nowadays?

Silvio - I had 2 of the Watchmeister DWs & was never able to get either of them to remain centered in the date window for very long

In the end, I switched back to the original MBW datewheel overlay & never had a problem again.

But once you swap out the ETA for the 1570, you will not have to deal with overlays anymore.

[Guest carlsbadrolex]

Blah blah blah...

You guys truly understand what is at the heart of every vintage Rolex lover. The time, blood, sweat and tears that it must take to complete such a project is unimaginable to me.

Congratulations to both of you and I truly look forward to seeing the finished project.

T

[jmt]

Blah blah blah...

You guys truly understand what is at the heart of every vintage Rolex lover. The time, blood, sweat and tears that it must take to complete such a project is unimaginable to me.

Congratulations to both of you and I truly look forward to seeing the finished project.

T

What I struggle with is what is the threshold... at which... you decide to make a franken for a boat load of money v. buy a lesser gen for less money. That is, I can buy a gen 5512 for ~$7k... while making a good dsrd will cost me +/-1200 the movement, the rep case @ say $500 and of I want a gen dial, say $1500 for that. Now, its a lot less than a gen dsrd, but not that much less than a gen 5512. I dunno. I am stuck...

[freddy333]

You make a very good point.

We each have our own set of qualifications, but my general rule of thumb for reps (& frankens) is that I will not spend more than 1/20th the cost of the gen watch for a rep. That is, while I will consider spending $2,000 buying the components to construct a franken copy of an $80,000+ vintage Paul Newman Daytona or $50,000 DRSD, I would not spend $2,000 on a rep or franken copy of a $5,000 or $10,000 gen watch. To me, that just does not make economic sense. Of course, there are exceptions to every rule & each of us comes to the table with a different set of emotions that often get the best of our rules. But I would seriously re-consider spending $1,500 on a non-gen watch when you can have the gen for $5,000-$7,000 (unless you REALLY have to have it & no off-the-shelf rep makes your grade).