With the techumseh, take of the starter (or the cowl if necissary) and see if you can get the cord to grab.
If not, wrap a cord around the cup, and see if it will start then, if not, I honestly would suggest kick it out, there's better engines out there.
The Honda on the other hand is a great motor, and should not be tossed, but really does not suit the base.
Decide what you would like to see happen to the 4 models (Hond, Techumseh, Rover & SS) then let us know if you need any parts/info.