Sears never made a gun they had them made by some one else. it could be a spring field and a JC Higgins. and winchester. the value sholud be from 100 to 150 depending on the quaity. It's a Winchester 1200 Field Grade with the Sears name on it. Valued as much as $200 as a Winchester in 100% condition. With the Sears name in good used condition, maybe $100-$125. PS. Springfield and JC Higgins didn't make guns either. Just names used by other makers.
your sears shotgun was made by savage arms.There model number was savage model 96.
I believe that your Sears shotgun is a Winchester model 37A shotgun that was made for Sears Roebuck And Co,.
No sn provided and there is no sn data for Sears.
It is a Savage/Stevens Model 94, and the barrel has been cut off. Value is minimal.
3 inch chambers are reletiveely new so it isn't that old
50-200 usd
It will be marked on the barrel, but that should be a 12 g shotgun.
Winchester
I bought a sears 684 shotgun (12 gauge) at sears around 1979 , for $ 99
Winchester, same as model 1400.
Marlin High Standard made the Model 75 20 ga semi-auto shotgun for Sears http://www.histandard.info/PDF/Sears%20Shotguns.pdf
Stevens