If it is a J.C. Higgins bolt action shotgun, there is a small set screw on the left side of the receiver top between the bolt handle and the ejection port. Use a flat tip screwdriver and take out that screw. It is litterally the metal peg that the bolt is running back into. Without the screw, the bolt comes straight out the rear.
Stevens
http://www.histandard.info/PDF/Sears%20Shotguns.pdf
The Sears Ranger 105-20 16 gauge shotgun came out in the 1930s. The Sears Ranger shotgun has a 26-inch barrel.
Sears Roebuck co.
Depends on model and condition. Typically $100-$150.
No age records, most likely a Mossberg shotgun, values $50-$75.
http://www.histandard.info/manuals/sears/bashotguns/index.html
The JC Higgins 583.16 is a bolt-action 12ga shotgun made for Sears by High Standard in 1948/1949.
about $100
http://www.histandard.info/PDF/Sears%20Shotguns.pdf
A bolt action shotgun in 12 gauge.
I believe that your Sears shotgun is a Winchester model 37A shotgun that was made for Sears Roebuck And Co,.