But this has been covered here. The Briggs in question is most probably the excellent Komatsu Zenoah engine of the 1980s Rover did buy these engines. It was a brilliant, refined motor.
See images below.
Cheers Jack
p.s. Also not that Briggs did make a small 2-stroke post WWII for snow throwing machines. I think these were called Snow Blower 2-strokes. I was told that these were made by ... Harley Davidson at Milwaukee - just down the road from Briggs headquarters.
Here is more modern Briggs Blower engine. I don't know its origin.
