I've never seen endlinks 174 and the clasp has no ref number. Another weird thing for me, not being an expert on Omega, the serial number starts with an R, I knew there are only numbers. Am I wrong?
IIRC the "R" indicates a replacement part on these movements. There are also known examples of "R" serialized cal 861s.
First time I heard that..if I did not read that and seen an Omega with that inscription I would have sad that is probably fake. Always room for learning...