I won this Irvine 40 on eBay for less than £12, ( about $17.50 US.) Had some misgivings about the scored piston, tightness of the piston in the bore at TDC, and the apparent play in the big end but I lubricated everything, stuck it in the test stand and it runs well. The propeller may look as if it's stationary, but actually the engine's ticking over!
http://i1143.photobucket.com/albums/...rvine%2040.jpg