many factories installed their own. poly-choke authorized factories and gunsmiths and assigned a code number to them. this is mentioned in Shirley's book on Auto-5's and the code numbers for the FN installed and the ones installed by Browning here are noted.
i asked the current company about a list of codes as i've had a model 12 with a polychoke with a number stamped on it and i was curious if it were factory but whatever records of what numbers were assigned to whom did not get transferred and they've no idea who was "authorized".
roger
