This is apparently a Vintage Seamaster but shouldn't the caseback be a Seamaster one instead of just a plain caseback?
http://www.ebay.com/itm/OMEGA-SEAMA...669973131?pt=Wristwatches&hash=item43ad47ce8b
http://www.ebay.com/itm/OMEGA-SEAMA...669973131?pt=Wristwatches&hash=item43ad47ce8b