Any specialists out there on Bausch and Lomb Protar lenses? I have a very small lens marked Bausch and Lomb Protar, AF 4231, set in a Betax No 1 shutter. Marked Bausch and Lomb OPT. CO, Rochester, N.Y, U.S.A; PROTAR VI 223MM. Is this a legitimate lens/ Any specifications available? Thanks.