lol...oh no, not the "vintage" inner tube cap BS....lol...but actually there is a certain "kind"
I just deleted awhile back the pic I took of various vintage 70's Honda caps..
You understand, that the caps are not honda but depend on what innertube you buy. So common tires were Bridgestones which came with bridgestone tubes....
So, what tires are on your bike, and let me see pics of the caps....Most were of a "dome" type. But they did change a little over the years, mostly the dome part.
If you look at a close up of the pic I sent....you can barely make out the style.