This is a Hi Johnson .35 model airplane engine with wooden prop built by Dynamic Models. It’s a glow ignition single-cylinder engine that first appeared in ads in 1955. This version has no paint on the case and no black oxide finish on the cylinder fins. It appears to be from June 1956. It has a needle body that threads into the venturi, die-cast connecting rod, and square port in the shaft. The engine also has a six-bolt head. It has a bore of .770, stroke of .750, and displacement is .349 cu. in.