I have a 1970’s vintage H & R 45/70. Shoots fine with everything I’ve thought to put in it over the years but sights don’t elevate over 100 yards. I would like to put a full buckhorn sight on it. Was thinking Marbles, like the semi-buck horn on my ’95 cb, but wondering whether that would work on the round barrel. Had other questions but the ’95 kind of answered them. Called Marbles, recording said to call distributor; distributor said to call Marbles. Is getting frustrating, like the rifle but not the sights. Any comments, ideas, suggestions?