Confirming in large part Zachary’s notes in his first posting, for 160788 the “book” says:
PT H 0 C 16 28
For clarification on one point, third column XT is for extras. The 33 possible codes are at page 61 of Price & Fjestad. XTRA Code 0 is for no features or options installed on a gun at the factory. Ejectors is one of the six features noted in the “book”.
As I understand it, frame sizes are not recorded in the Parker factory records. I for one, wish the frame sizes were noted. But of all the features on a Parker Brothers shotgun that can be altered, frame size is rarely (if ever?) changed. I can measure for frame size anytime I want, and do it all day long and feel solid in my confidence that I am looking at the factory original configuration. It seems that every other feature is “up for grabs”, limited only by the ingenuity of the person doing the gunsmithing work.
For example, hammer to hammerless:
https://www.remingtonsociety.org/an-...by-louis-diss/
I did read about a guy in England who says he “once converted .177 BSA airgun into an O/U 16 gauge side lock ejector using a kit from Woolworths”. He said “it was quite an easy conversion, only took about three hours”. A friend of his said “don’t laugh, gave my friend a lift to Woolworths for the kit and got booked for a parking offense”.