Okay, update.
A little JB-as-body-filler goodness for you this time. I'm going to have to sand and do a 2nd coat, obviously. But since jbweld takes powdercoat, I'm using it as I would bondo to make the backside of Goliath a bit prettier.
Before (all sanded and cleaned off)
After (gunk in place)
The nice thing about jbweld is that you dont have to be too careful about creating voids or putting it on too thick. Its strong as hell one way or another, and it has a tendancy to 'slump'. The slumping lets trapped bubbles escape, something that does not happen with bondo.