Tks Roger. The rings are stamped with the same sequential numbers as the cradle portion, so whenever it was built those would seem to be the rings with it, and the whole unit was blackened together. I think the rings were simply filed / ground heavily and not finish polished. Looks like file marks on it in spots. The last 4T rig I had, sold last year, had a much much nicer (prettier) mount.
Regards,
Craig