Yeah, my hardest part is finding time to work on it. 5 kids all under 8 keeps me busy. I also was looking at using a bottlecap to hold the battery in. But I have been tossing up the idea of making the cap the switch and using magnets to keep the switch open until you push down on the cap.
It will cost me a bit more because I do not have parts laying around the house. So I have to
buy stuff to tinker with and hope that it works.