A 4 gallon "BoaTank" with a float style gauge/cap assembly was used. We looked on the web for information on the Manufacturer, Bettcher Manufacturing of Cleveland Ohio, but found little on this type of fuel tank and gauge.
Our gauge is a bit worse for wear, unfortunately the glass cover is broken.
A rubber pad held the tank tight against the fiberglass shell to avoid rattling. And the float unit is very corroded and in marginal condition. Hopefully some Evaporust can clean it up well enough to reuse.
The tank mounted to the body with two carriage bolts and a piece of plumbing pipe strap. Industrial, but effective.
The fuel line ran down the right side of the hull, pop-riveted into place with small plastic clips to retain the fuel hose in place. Oddly, some pop-rivets were steel, some aluminum. Possibly past owner repairs.