Some detail on your Briggs engine. It was made on 4 November, 1975, as Deejay said. Location was Briggs' Rolla, Missouri plant - one of the few that is still operating, though it no longer makes side valve engines of course (only Briggs' Chongqing plant makes them now).

Here is the Illustrated Parts List for the engine:
http://bsintek.basco.com/BriggsDocumentDisplay/Z6jmyBVJ1DajI.pdf

Here is the Operator's Manual:
http://bsintek.basco.com/BriggsDocumentDisplay/flivAJX-nfBhU7y.pdf

The engine has a displacement of 8 cubic inches (130 cc), is of the first design generation, has a horizontal crankshaft with a Pulsa-Jet carburetor, with plain main bearings (not ballraces) and a recoil starter. Being pre-1982, it has breaker-point ignition, not electronic ignition.