The motor does look like a '26, more than likely a '27. The casting number above the dist. h 3 7 i believe is the casting date-- Aug 3 1927. The exposed push rods, single exhaust port also are characteristic of the '27. In the last photo of your "puzzle" on your site, it is the throttle shaft(gas pedal). If the motor is beyond rebuilding, I would like to purchase some of the parts from you.
Cheers,
Andrew
