It is extremely rare... If it is a pocket watch only an Omega Extract of The Archives. will can tell that.... Dan
I think these trench watches are lovely – but not particularly rare – because a lot were made. They often have silver or gold cases. The movement is a savonette/hunter (not specifically a pocket watch movement) and the 13’’’SOB and 15’’’SOB were both used in large numbers in these watches. Lots of examples in AJTT pp. 106 – 109. Of course an Extract of the Archives should confirm things for you, but I suggest yours dates about 1916. As an example, one sold at auction last week for about $500. Granted it was not running (a small problem!) but it had a beautiful solid gold (15 carat) gold case (and original crown!), as follows:
Is yours 41mm ? Not seen to often, 41mm. That is if the extract says it was issued as a wristwatch. Keep us in touch.