I am totally new to this forum. Well, I came across this site last week, and have spent "many" hours since. I do have two Omega Seamaster f300Hz. Anyway, here is the Seamaster I have been searching the net for another one like it but no luck yet. The movement is 520, and the seller claimed 1957-1958 production. What I feel strange is that the OMEGA and Seamaster letters are different from what we used to see. Anyone here can get me some advises? Many thanks.