I have a shutter mounted (may have been barrel originally) 24" Red Dot Artar with serial number 045. All it says on the lens is " APOCHROMAT ARTAR 24 IN. F:11 NO.045 "with no mention of Goerz or Schneider. The lens is superb but why no mention of manufacturer and why the really low serial number? Any insights appreciated! I'll be listing it on the Bay soon as I don't really need it.