I am going to post a few older pix from the start of my heater box restoration. The box was warped and did not fit together all the way, and was under constant tension trying to hold it clamped shut. I ended up cutting slits in the fiberglass, adding a mould release agent to one side of the tongue and groove for the case, applied a fill n sand putty, in the groove, and to the cut fringes, and clamped it together. In a day or so i popped it apart, sanded it a bit, and fiberglassed it. This now allows it to be set in place as 2 pieces and not forced into position. I still need to apply a good fill n sand primer, and a semi flat black to it.
I also made some nifty retainers for the cable ends instead of the round ine use only snap rings. These were made from #10 aircraft tool drill microstops. With a little set screw in their side they can be removed and reinstalled if you should have to pull it all apart.