sears roto spader 785.290030

Looks like a Magna built tiller to me Bunker. And looks like the motor has been replaced with a later Tecumseh. Make sure the motor has an iron flywheel. A motor from a lawnmower that has an aluminum flywheel won't work. Aluminum flywheel motors need the mass of the mower blade to carry the motor through it's cycle. If it's what I think it is then it has a cone type clutch. You could still buy the clutch lining a year ago but I think they may be gone now.

Bunker has clarified that the tag is on the tiller and not the motor Bill. I could be wrong but the motor looks like later lawnmower motor. Either way it's a cool old Rotospader.