Thanks for all of the input...I finally decided to use some aluminum flashing from Home Depot to fashion a backplate of sorts using the back of the engine as a template. The flashing was super thin and light, yet rigid. I just drilled 4 holes for the engine mounting screws and slid it on the standoffs before tightening down the little Toro 25 GT.

This is a sweet little engine for sure. I think I'm gonna run it awhile with the magneto for simplicity, and then upgrade to the electronic ignition later. Again, thanks for everyone's help.

Mike