Many have asked me privately and on here about the part number and sizes for the Omega dome I use that fits 1601 and 18XX DJ/DD.
I nipped in to see my watchmaker this morning and he doesn't have any in stock but he assures me the part number is OMG 306296 and he believes it's for the one of the vintage Sea Masters.
My advice to those twittering about using the Rolex T21 is to save your money. I bought an absolute original one out of a roll for $200+ off a well known and very trusted member here. Now whilst it fitted fine and looked very nice we could not get it to hold any kind of vacuum. For me a non waterproof Rolex is pointless and ceases to be a Rolex any more.
The risk with the T21 is also very high - 99% are gonna be fake and any real ones left really should be used only in their rightful Cosmograph seat. That model needs to be kept waterproof and original as possible IMO.
Also for 10% of the Rolex cost you can fit the Omega item, it'll look nice and be assuredly water proof.
I had one pulled just now and took these snaps. I hope this is of help to those who have asked me the Omega question and considering a T21 as an option.
have a nice Friday everyone
EDIT: I just found this online: