I can't answer directly, but if they were mine I'd think they were a neat thing to have and not use them. Ring technology has come a very long ways since 1963 and I'd rather run a modern moly faced ring, with the bore finished for that style. Even if the pistons had an odd sized ring land, any of our good vendors on here could order a custom ring set designed for the intended use. Face coating, finish, tension can all be dialed in. Two most important things I've found over the years is ring seal and precision cylinder head parts and machining. And bearing clearances. OK, three things. I'll come in again...