So I know this is an old thread, but I will try anyways. I just bought a L23xxxx 16610, and it seems to have an open 6 date wheel. I thought that was reserved for older refs, so tried to search around. I have only found sparse information on 16610 refs with flat four and open 6 and 9. Is there any official material or ways to check that this is indeed original to my watch, or if it could be a service part? I would like the watch to be as original as possible (as delivered from rolex in '89), but it is also a very nice addition of the "more vintage" date wheel. I forgot to check if it had a flat top 3, and could this be a tell of originality, heard that some 16610 has the open 6/9 and flat four, but not the flat 3?
Any information on this is highly appreciated!