That appears to be a 35205000.
Bit of misinformation in this thread. The serial number on this watch will be engraved on the case back, not on the lugs - see picture below:
These can wear away or be refinished away pretty easily, so you want to make sure you can read it. The reason is because there is no serial number on the movement - Cal. 1151 is not a chronometer and I've never seen one with a serial number. If there is no serial number on the case or movement, Omega will refuse to service it. That isn't a complete catastrophe by any means, as plenty of watchmakers can service this movement, but it does remove one major service provider and may affect resale value if that's important.
Cheers, Al
Click to expand...