Keystone Klassics: Originals And Newer Uni-Lug

I’ve got the uni-lug rims with the stamped steel chrome caps but am looking for the cast caps of the late 60’s. I’ve found someone who has some the same diameter but he says they won’t fit the uni-lug rims. Has anybody fit the older style cast caps to the uni-lug rims? Really want that Sox & Martin Keystone look. Caps cast like the two on left shown in pic

I'm looking for four of them smaller diameter for small bolt pattern keystones....very hard to find them...usually very pricey when you do