Could someone please tell me what options there are for an Omega deployant to use on a FOIS. I am particularly interested in the "short" deployant clasp. Does it come in a 16mm size? Does anyone know the part number of that that clasp?
Yep, there is a deployment clasp for the 19mm lug side and 16mm clasp side as a clasp standard or short length. The wrist size opening (with deployant and strap) is affected when you slide your wrist through, but not so much how it fits on your wrist when all is cinched down. If a small wrist is the issue, I would recommend first trying out a short strap length with a standard deployment. A standard polished throughout deployant for the FOIS (19/16mm) is 94521613 and a combination brushed and polished is 94521643.
I own both 16mm deployant clasps (short and regular version mentioned above) and both works well in my case. As said above suggest you tried them both before buying as the short one may or may not go through your fist depending on how big they are.