The tri-stock was added on the sides, not the top. Had to glue the tri-stock pieces to a small dowl and push it into the epoxy. Once the epoxy was dry, I snapped the dowl off. I then poured in more epoxy over the tri-stock at a 45 degree angle and layed the fuse on its side so the epoxy would coat the side walls of the fuse. This was all done through the fuel tank compartment.

You can see from this picture that I screwed spruce members on each side to front of the firewall. The screws go all the way into the tri-stock. These members sandwich the firewall between them and the tri-stock and replaced the blocks used attach the cowl.