Vintage Seamaster need help

Hi everybody, i am new to this forum. I received a gift from my father and it has been in the family for generations.

Next week i am going to look for a watchmaker that can open my watch and tell me the exact serial number, mecanism and case number. Until then i wonder if somebody have a brief idea of the year of manufacture and case number. I tried to look with a magnifying glass on the back of the peg and i see some numbers but i cant read it because the watch is very worn out and theres a lot of scratches.

it is a Omega Seamaster automatic in what appears to be a stainless steel case. On the back it says Seamaster and Waterproof. Does anybody have something similar that can point me in the right direction for my research ? Thank you !

Nice watch with honest and nice patina on the dial! It s a coathanger-S-Seamaster . Just service / clean the inside of the movement and polish the glass by a watch-maker! Nothing more!

thank you !