Finally got it working, sort of. Still have some leveling issues. The pump is a Tetra aquarium pump and the damn cord was six inches shorter than the old cord, which resulted in comedy when I tried to make the thing reach to the extension post in the garden from where it was perfectly lined up with windows etc.
I think part of the problem with the leveling is that it's been disassembled, reassembled and caulked so many times that it's not fitting together quite the same way. I shoved a rock under one side and that fixed it a little, but not too much.
I hot-glued pennies to the bottoms of the eyeballs so they wouldn't roll.