My understanding is that the first true gas operated automatic shotgun was sold by Sears & Roebuck in 1955 as the J.C. Higgins Model 60 and was manufactured by High Standard.
You would have to list the model number of your shotgun,to identify the maker of your sears and roebuck shotgun,in order to get the correct buttstock.
I believe that your Sears shotgun is a Winchester model 37A shotgun that was made for Sears Roebuck And Co,.
$25
High Standard
Check the barrel and receiver.
with the serial number that you provided,your Winchester model 12 shotgun was produced in the year 1935.
The value of a Sears and Roebuck 12 gauge shotgun model number 281512651 depends on its condition. This gun in excellent condition is valued between 100.00 and 135.00 as of 2014.
With the serial number that you provided,your Winchester model 1912 pump action shotgun was produced in the year 1950.
Old gun catalogs, old Sears & Roebuck catalogs.
Without a model number and the condition of the gun, impossible to answer.
The Sears Roebuck Model 20 12 gauge shotgun, serial number 5832006 is valued at $200 in very good condition. It good condition, it is valued at $125.
With the serial number that you provided,your Winchester model 12 pump action shotgun was produced in the year 1928.