Well, her point is that I've already GOT the OS 160. I also think she sees the writing on the wall. If I pop for a different engine in the Cessna, then that will leave me the 160 looking for an airframe. She didn't just fall off the turnip truck.

Thanks for the information on mounting the battery. It looks to me like you just use longer bolts for the engine, and the portion that extends is used to fasten the ply for the battery. Pretty slick idea. Do you use any kind of rubber washers with the ply to absorb vibration or just rely on the foam?

I could see using a standard flat nut for the engine itself, then flat washer, rubber washer, plywood, another rubber washer, flat washer then a nylon lock nut. Overkill?