Alligoat covered almost everything, so I will just add that the main obstacle to creating an (accurate) 6538 is locating the 8mm Brevet crown, which will likely cost as much (if not more) than all of the other parts. An alternative would be to shift down to the 6536, which is similar to the '38, but uses a standard (& much less expensive) 6mm Twinlock or Brevet crown
General rule-of-thumb for Rolex pearls (this is not a hard-&-fast rule) - if the index markers on the dial have metal surrounds, so will the pearl. If they do not, then neither will the pearl.
You can probably fit a gen crystal to it, but it may not be the correct 1 for that model. Since the case is not made to the exact 1665 dimensions, finding a crystal that fits will require a bit of trial-&-error. You might start by removing the existing crystal & measuring the height & inner & outer diameters. Unfortunately, I do not know of a source that lists the dimensions of all gen Rolex crystals, but someone else might.
Sorry, Guys. I just found this thread.
This 1 (which contains a transplanted rep dial & gen hands/pushers/crown/tube) is going on 5 years old
This 1 is about 3 years old (same movement)
And this is the 1st watch treated with graphite powder (still running)
The dimensions of Clark's T39 are the same as the gen. I do not have a Silix SD so, as was already mentioned, the only way to know for sure is to try it, but I doubt it will fit.
Unless you get lucky & find a 1-off run from some independent seller, the NDtrading dial is about as good as you will find.
But keep in mind that the small handful of people who will know (or be able to appreciate) the difference between a double red & a double Martini are the same people who will know the difference between a gen dial & all the aftermarket or a so-called 'repainted' dials.