Looking through catalogs -

Parts catalogs, 1948 no 7A, Nov 1, 1951 7A listed and shows a bent sheetmetal trigger guard for it (a Model 15 part No.) and a cast guard for the 7.

Product catalogs -
1946 price list - Model 7 listed as having checkered wood and being drilled & tapped for Weaver scopes, also the 7S version describes the No 100, No 105 & folding rear sight set.
1947 thru 1949 - Model 7 not listed, nor is the Stevens version, the Model 85.
1950 & 1951 - Model 7 listed, no mention of being drilled & tapped for telescope mounts but is for the No 150 receiver sight.
1952 to the 1960's - no Model 7 but the Stevens 85 is still listed

Product catalogs do not list the alpha characters with the model numbers.

Last edited by GeneB; 02/24/17. Reason: added last note

Gene