Dave that looks like Holt Bros. Engine off a Caterpillar. Very early model, we have a caterpillar club here in Salem or. that I am sure can give all kinds of help on parts and other help. http://beta.antiquepowerland.com/ Go to this site and call them to get in touch with the club members. Walt Davies Cooper Hollow Farm Monmouth, OR 97361 503 623-0460