I bought this completed Hired Man engine a few years ago. It comes with a set of plans. The base appears to be maple, it measures
2" X 9" X 17".   The flywheels are 6".  The engine size without the base is 7" wide, 12 "  tall and 13" long. The gas tank appears to be cooper.  See in the underside picture the electronics.  I have never run the engine.  It has great compression.  Please ask questions before bidding.