Pre-purchase Omega automatic Seamaster input

Hi all. New to this site. I am considering purchasing this watch from a good friend’s fathers estate. By my own principle i am trying to purchase the best that i can afford and i would like to wear this more often than not. Trying to identify exactly what I have along with the year and a fair price for both parties.. All I know about the watch is what I can figure out from looking at it. OMEGA automatic Seamaster. Underneath the 6, I can read small letters, " swiss made ".Stamped “750” inside rear , on the band & on the casing . The watch is 34.5mm & works well. Total weight is 111gms overall very good condition . Case Number 166003 ,Movement Serial Number 28951320 Any help / information would be very much appreciated. Thank you all in advance.