I don't know,but I do think this motor has come from another mower.As why would you have the tank hanging from the right hand side.As when these where made the tanks were on the front and supported by the cowl.So I would say this motor was from some kind of VC,not sure what model.I guess the project was stopped due to problems involving,like where does the tank go now?I guess there thought was what cowl,we won't have one now.

Here for a good time,not a long time.