gas cap

Ouch!!!

Yeah it’s usually much cheaper to buy a later filler tube and cap.

GPS tracker is a good idea, I wonder if one of those deals for you car keys, etc could be adapted. Or maybe just put it on a cable.

The one I have is a ‘74, I parted a ‘74 swinger so it’s just what I had.
Actually, I took the cap that I bought, measured the 'guts' and modified a 67-71 A-Body chrome fuel cap I got from Classic, part # MA8174, using a dremel, and if fits the duster perfectly! I am going to modify a couple more (1 chrome, 1 primered) and document it and put it here on the forum.

The only thing is the chrome cap doesn't have the 'pressure relief valve', it's just a plain cap. It does have the rubber seal which should suffice a vapor barrier.