[timebroker]

The serial number suggests that it is from late 1951 so him having it sent to Omega and saying it is from 1953 seems odd, maybe it was produced in '51 and sold in '53 dunno.
The 321 caliber was used in Seamasters between 1946 and 1968 so that one is quite early.

My only problem I have with the watch are the hands, to my knowledge they should be dauphine and not the radium type.
All the Seamasters in gold from that period of which I have pictures or seen in real life had dauphine or semi dauphine.

It should probably go a lot higher than 2500 dollar so be prepared to pay 4000 maybe even 5000, these are very rare and collectible.
A private collector I know payed 4500 a couple of months ago for a similar seamaster in gold with 321 cal. of that era.

Good luck.

Oh yeah, I would ask if he has the original servicing paper from Omega, that would clear everything up!
Excellent redial by the way!
Could provide pictures of similar watches from Omega advertisements but I have to look for them :)