I used a Perko filler cap that is vented to the tank for filling and to outside air for running (won't pull a vacuum)
I welded a ¼-20 nut inside my light housing and a fender washer outside. A ¼-20 bolt is my hinge.
The bulb housing was cut out of the lens frame; a back and bushings were welded in place. The bottom is slotted to route wires
This plate was welded in the stake pocket
A 1 ¾” piece of muffler pipe was bent to 90 with one end stretched to 2” to match the filler on my fuel cell. A piece of 1-1/2” muffler pipe was welded in the other end to match my filler neck.
A push/pull cabinet hinge was used to hold it closed and open it.
I’ll need to drop my FCG tank ~1” to keep filling downhill.
I still have some trimming to do and I’ll close up my stake pocket. I’ll also weld my 90 in to keep things from rubbing.