The Sel-A-Vision is based on a Gilbarco 996 and 906. These two model of pumps were made from 1947 to I think 1953. I have seen unrestored example of both 996 and the 906 so that would tell me they were made for more than one year. I have seen them in Chevron and Flying A in unrestored condition. Esso used Gilbarco pumps exclusively so they would be a good candidate. Gilmore was fazed out by 1945. Here is a picture of an N.O.S. tape that I saw on ebay years ago.

I like shoebox pumps [Linked Image]