So I think I have it... Premium epoxy (eg. West Marine) and micro-balloons. I was originally going to use marine gelled resin, so it would not creep down while curing. Must get my ducks in a row when I pick it up from the widow in April. Should fit in my garage without resorting to temp 8" wheels. Unit has original style 13" tires
. New sizes are higher profile, I believe...Cheers!