Don Nave's engine solved:  Gilson "Johnny on the Spot", type JS, 1 1/2 hp, built between 1913 and 1916.  The original ID tag would have been mounted to the crank guard which is also missing.  All Gilson's of this type have their intake from the bottom and exhaust out the side (right in front view).  The rocker for the exhaust on this engine is home made and the previous owner did not know that he set it up on the wrong valve!  Believe it or not, this engine does run.