your sears shotgun was made by savage arms.There model number was savage model 96.
http://www.histandard.info/PDF/Sears%20Shotguns.pdf
No sn data available.
No sn provided and there is no sn data for Sears.
I bought a sears 684 shotgun (12 gauge) at sears around 1979 , for $ 99
What model????
http://www.histandard.info/manuals/sears/pashotguns/index.html
Its a Sears branded Mossberg 500.
It is a Stevens Model 250A, made by them for Sears, using the Sears J.C. Higgins trade name.
Sears Slug Model 446.511761 is a Mossberg 500. All parts interchange.
Winchester, same as model 1400.
Need model number