Now that the reversing valve is working, I was wondering if you might go back and look at valve tweaks that could make it also a throttle, like you noted in a previous video. That would really make it a complete package.
I've seen the plans for this engine and one like it that is rotary. The value for each piston is in the adjacent cylinder. Quite a clever scheme. While he doesn't use a metal lathe (like me), he does use metal for the piston/valve, cylinders and shafts. If you want to see an all wood...