perthmower, to clarify the information you have supplied, your Briggs engine is:
Model 80102
Type 0233 Trim 01
Code 7603208.
The first digit of the model number is the displacement in cubic inches, the second is the design generation of the engine, the third tells you it has a horizontal crankshaft and a Vacu-Jet carburetor, the fourth tells you it has plain main bearings, and the fifth tells you it has a recoil starter.
The type and trim are indecipherable to civilians, but it indicates what combination of options the engine buyer (Scott Bonnar) has specified, right down to the kind of decals on the engine.
The code specifies, in reverse order, the day, month and year it was built (20 March 1976) and that it was made in Briggs' Plant 8. Plant 8 was closed some years ago, along with quite a few other Briggs plants, and I can't even tell you where it was located now. (Briggs has moved all side valve engine production to its plant in China, and now only makes OHV and DOV engines in the US.)
With the Model and Type, we can look up the original Briggs information for the engine. Here is the Illustrated Parts List:
http://bsintek.basco.com/BriggsDocumentDisplay/Z6jmvGVJ1DajI.pdfHere is the Operator's Manual:
http://bsintek.basco.com/BriggsDocumentDisplay/lrvvA-wU7eL7hAxB91ObQ.pdf
