Yes, it was made on 5 May, 1981, so you have one of the last Briggs engines to have breaker points (they went electronic in 1982). I can't tell you which of the US plants built it, since it has long since closed, and consequently isn't on my list.

In case it helps with the restoration, here is the Illustrated Parts List for your engine:
http://bsintek.basco.com/BriggsDocumentDisplay/Z6lttJVJ1DajI.pdf

Here is the Operator's Manual:
http://bsintek.basco.com/BriggsDocumentDisplay/msoBGL-K_ny7tH217FzoPu.pdf

You already know that the engine has a displacement of 25 cubic inches. It is of the third design generation, with a vertical crankshaft and a Flo-Jet carburetor, plain main bearings, and a 12 Volt gear drive electric starter. Being a 1981 engine it is covered in the Briggs and Stratton Service and Repair Instructions 1984, which (along with all of the other Briggs general repair manuals) is available for download from the manuals section.

Last edited by grumpy; 11/12/13 08:10 PM. Reason: Add detail