Where to find OEM Bezel Replacement Part Number?

I am in need of an OEM bezel replacement for my 3510.12 (circa 1996). Is there a database or product sheet or some means by which you folks figure out the original part numbers for things like this? I realize that I can just have this done next time it goes in for a service or with an authorized Omega watchmaker.

This is as much to satisfy my own curiosity on identifying, sourcing and perhaps even performing seemingly simple tasks like this...

Here's the watch in question:

Google....

Yea? WHATS wrong with it? Looks ok from here ;-)

The edge of the bezel between 4 and 6-o'clock is faded away - that's not a light reflection. I also didn't notice it in the sales listing. I was googling around for some time - didn't have any luck finding correct part numbers. Thanks for the part number and the warning on the complexity for this one.