I have mounted fuel tanks in all my homebuilts since the KR-2 in the 1970's the same as I mounted the fuel tank in my pipe buggy. Take a short length round 4130 tube drill a 1/4" hole and insert a 1/4" bolt and tack weld the head. Made tank straps from .025 or .032 aluminum. Lap the straps to get the correct length and rivet. I use 1/8" thick belting as a cushion on the fuel tank in all contact points. The tank is about 15 gallon. Made from .050" 5052 aluminum. Has 2 baffles.