Hi As the title says I am finally in a position to have my cal 321 movement serviced. The watch is currently with STS but they are waiting till i source a part** to make the 321 period correct. I asked for the following work only. - Service movement - Ultrasonic clean case - no polishing etc - Colour match missing lume on minute hand (purists may disagree but I would rather have it looking decent) - Polish Crystal So pretty minimal stuff in an attempt to kept it as original as possible. Is there anything else I should ask for ? My question to you speedy collectors what are the thoughts on replacing the crystal ? STS asked if I wanted it replacing but I have declined so far. My understanding is that the original crystal is shallower than replacements - or can people confirm a part number that would be identical ? Put another way with regards to keeping it original; is a crystal replacement deem acceptable for a vintage speed master? **Referencing the Moon Watch Only mine is an early 105.012 featuring a 321 2nd gen and therefore should have the symmetrical clutch coupling bridge as opposed to the asymmetrical that is installed at the moment.