I have one. Was made for a boat. I say that as the box had a marine name on it. Look close, you can kinda see it on my avatar ok maybe not. But its on the model T thread.
No need to look elsewhere, he his it covered. The hard part is figuring out which one to choose, there are so many!
Here is the swedish one. Its on a -33 chevy 3w and vill have a Csb 350 with a Dyers satib finich 6-71blower, so the gascap is perfekt with the satin finish also.
This one I put on a '29 roadster. Made in Italy, likely for a bike, but not sure. It's stainless, with an aluminum base. With a little mod, it screwed right on and sealed well.
Here is HAMB member corn boys, flip top cas cap on his banger powered roadster T. Scored at a swap meet, make and vintage unknown.