This sad wretch looks like the Rosetta Stone of nearly all of the problems that typically plague reps. It is really a crap-shoot out there, guys. And if ever there was a good reason to buy even the simplest of watchmakers' tools (so you can at least remove the caseback), this is it. Though, to be fair, I have seen similarly nasty stuff (though not to this degree) inside a couple of Phong's expensive franken-tonas.
I cannot tell you about Pan upgrades (I no longer own any Pans - pocket watches with straps are not my style), but, in general, while you are correct that the average taxpayer will not know the difference, it is not a good idea to take a rep watch to a gen dealer for repair. Most likely, they will (know the difference).
As far as I can tell, all 3 use the same case. The differences are in the ancillary parts & assembly quality (or lack thereof), which varies considerably (with each leaving alot of room for improvement/correction).
I think what you have done looks very good. You might try Nanuq's trick of putting the watch case (remove the movement 1st) into a can full of coins & give it a good 5-minute shake. The coins should do a good job of aging the case & bracelet. Beyond that, I think the watch has too many irreconcilable issues to make it worth putting much more effort into.
DLC is not my thing, but it does look good. I wonder how the finish will hold up since the owner does tend to WEAR his watch? Am I correct in assuming that DLC cannot be polished like the original steel can?
It is true that alot more people look at watches (& decide whether they think the watch is real or not) than will ever say anything. So, while it is very rare, in my experience, for a stranger to comment - good or bad - about my watch, I am aware that most people are thinking about it (sizing me up against my watch - do I look like I could afford the watch I appear to be wearing).
Only (new) friends will generally ask about a watch & I always say 'rep'. This of course causes uncontrollable giggles from my long-time friends since they know I am usually wearing either a gen-powered franken or a gen.
I do not know why (since, in my quarter century of collecting watches, I have only ever had 1 stranger - a waiter - ask about my watch), but this has to be 1 of the most frequently asked questions by newbies. Some people must travel in very suspicious circles.
Sorry to hear you have another dead watch. Josh may have had a bad run of watches (remember, the movements in rep watches are used &/or unserviced), so you might try for the same watch from another collector. Another option (since it is always a good idea to have any rep you plan to keep serviced by a pro watchmaker as soon as you receive it) would be to have the watch properly serviced by a professional (rep-friendly) watchmaker. Post a request for help in the repair section or check your local phone book for watchmakers (I would specifically ask whether they work on reps before making the trip).
That is alot of money for a franken (at best) or rep (at worst). That auction contains all the hallmarks of a scam (no good clear pics, no bracelet, no movement pic, no returns, etc). My sympathies to the buyer.
Manually wind the watch 40 turns (yes, again) & then pull out the stem to the time-setting position & run the hands through a complete 24-hour cycle. Press the stem back all the way in (make sure it is all the way in, otherwise that may be the reason it will not start). If it still fails to run, I would then request a replacement (not repair). I would also request that the replacement watch be shipped out immediately (without having to wait for the 2nd defective watch to be returned). If the seller refuses, then request a refund & take your business to another seller.