Can't give you a date. But here's a bit of info for you: Numrich Arms' catalog #26 says that the Sears 101.40 was built by Stevens/Springfield (both affiliated under Savage...not sure of the relationship) over the years. Apparently, a change from one manufacturer to the other was made at some point during the era that Sears offered the model.
Also, Numrich (e-gunparts.com), does appear to have some small parts for the gun in case you need some replacements:
http://www.e-gunparts.com/products_new.asp?CatID=9675
http://www.e-gunparts.com/model_new.asp?catID=5602