Kerryman, your contradiction on D and F could be correct. However, I just went over to Guns International, and every F gun they show is built on the Facile Princeps action--which, fortunately, is very easy to spot. Unfortunately, they don't show any D Greeners. But my DH25 was most definitely an A&D gun, tang safety, auto ejectors. However, I don't have the Greener book and will be interested to see the answer to that one. G certainly denotes a higher grade. But then Greener made some models (Farkiller and Empire probably being the two most commonly seen) that weren't denoted by any letter.