Thanks very much for the abundance of information. I owned a couple of these that were purchased in the late 70's. I'm looking at two now (one with ejectors and one with extractors)that are apparently dated in the mid fifties to early sixties according to my newly acquired education. I thought they were a good buy back then, but these older models have surprisingly sharp checkering as opposed to the flattened patterns that seemed to be the norm in the 70's. One of these seems to have lost a piece of filling at the muzzle where the rib is joined. Could a drop of solder in the cavity adequately fix this?