Hey buddy,
For your modification work, since you want to stay in the EU for customs reasons, I would probably recommend Domi/bricciola for the job
As for the 16610 bezel- If it's gone bi-directional, it's probably just a matter of adjusting the click spring. It's possible that it's out of alignment and not engaging in the ratchet teeth, or it may need to be re-bent, or replaced if it is damaged. I don't think you need a new bezel assembly at this point, unless you just want to replace with gen for the aesthetic change and difference in feel.
For the 93250- I believe it does fit, but the SELs might not be as snug as a fit as the WM9 pieces. watcher did this swap on one of his WM9's, I seem to recall; I think he would be a good person to inquire on about this since he has first hand experience.
For the 5513 stuff-
If you are looking for a dial, I might have one that may work for you. It's not perfect, but it's very usable.
The 5513 uses the 1520 inside- This is the non-chronometer movement. Beat rate is 19800bph, so any 2846 or 2783 will be a close match (slightly faster at 21600bph).
Hope this helps!
Cheers,
//ubi