Chas, your right about the offset hole in the chassis for the shaft, thats only because that's the way the engine has been fitted on your model Greenfield.
the engine mount holes will still be same in relationship, it's a standard size thing.
all it means is that any engine will bolt to your chassis in the same position, ie, east/ west. you would only have to redrill the chassis if you wanted to mount it north / south, which most likely wont fit because the reason Greenfield turned the motor sideways to make them more compact. so there wont be enough room.
and.....it would centralise the shaft, which that model is not set up for.
just find a good engine and mount it the same way as yours is now, easy!
