I recently purchased a 1958 Seamaster in a 14k gold-filled American-made case, and would like to identify the maker of said case, and I could also use some info on the reference numbers inside the case back. Any help would be appreciated.

 

Not much to know. There is little to no information on US market cases.

Jenson made case.

 

That is the trademark for Jonell Watch Case, Inc. of Long Island, New York.

 

Doh your right.

 

Here is a screen capture of the 1955 Norman Morris catalog listing your watch in the lower left: Model G6250 in 14K gold fill, with sweep-second hand, price $120.

Norman Morris was Omega's U.S. distributor and it cased movements in American-made cases.

 

Thanks for the information. Very much appreciated. I've seen that maker's mark on a few other watches I own, but with only a single letter to go by, getting any leads on it were fairly impossible.