Perhaps you've gotten answers by now, but if not, your 1894 CB ought to have come from the factory with a plastic plug in the magazine which limits capacity to 10. It can be removed. I do not remember what the increased capacity is. Starting in 1973, the year of manufacture can be determined by subtracting the first two digits of the serial number from 100: Example: SN 2512345 would have been made in 1975 [100 - 25 = 75].