JUR is a good idea. I'll look into getting one locally.
Some progress today... I finished up the woodwork part of the build, and sprayed on a coat of black tinted polyester resin over the whole tank:
The pic with the wood covering the tank is just to keep the heat in... I set up a 5kw electric heater blowing into the tank to make the resin cure.
I also did the fiberglassing of one seam this evening... unfortunately I don't have any mat left, I thought there was more in my stash, so I'll need to get more before I can continue.