Mike,
so if that fails, (and i hope it works!) Maybe you could cut away the outer part of it, with the holes, and save the center ( it seems fairly flat)
That way you would still have the contacts and hub intact, and then make the outer portion of the ring from aluminum sheet and rivet it to the "bakelite"
What size are the holes for each card? I might have some punches the right size.
What is up with the extra rivet on the inside near the "8"? See any reason for that?
Bob