Bob, thank you, I'm hoping for the best. Last time I used Bondo was to patch a storm door, I learned to use as little harder as possible. Yes, I did sand the area that I'm going to fill. Happy your on the way to solving your problem with the system. Stay Well
EDIT: i just applied the first area, not quite all the way but am satisfied with how it came out. The 'hair' in the compound made it a bit more difficult to mix and apply as it had a tendency to draw more off than I wanted, but I'm learning and happy with it so far.
I just made a quick air tank up from a piece of water pipe and some wood plugs. I had to ream out the pipe to get the plugs in. That was easier than sanding the wood!
I still need to make another or a mold?
I didn't wish to rip apart a good engine for a copy....