I think these were in the Tower catalog up until the last few years. There is probably a hobby shop out there with one they would like to sell. I do see parts still available on the Tower website

i have one that is over 40 years old. One of my retirement projects is to put it on a plane. It ran great on a Sig Cub way back. I sort of remember it sounded like a sewing machine running.

Since they were sold over so many years I am sure you will find a few. Let us know

Regards

bob