DblFixer,
Graham Greener's book on Greener guns ("The Greener Story") details the various Greener models and associated features. The book is readily available from places like amazon. The books includes many photos which is really helpful. I recommend the book
As others have posted, if you are lucky, the model designation is located to the rear of the trigger guard. But if there is nothing there, there are lots of other features the distinguish a higher grade Greener gun. One note of caution though is that there are lots of exceptions to the rule - e.g., the lack of engraving on otherwise high grade guns that Eightbore mentioned. At the top end, the presence of the gold engraved crown and scepter is a give-way. Hammerless high grade guns usually had arcaded or serpentine fences and came with a bolstered action. Extensive engraving, heavily figured wood, the presence of things like horn inserts at stock wrist, and intricate checkering are also indicators. But again, by themselves are not definitive. I have a Greener royal "G gun" that I can snap some pictures of and post over the weekend that may be helpful.
For a fee, Greener will check their ledgers and provide information on a gun if you provide the serial number. You can contact them thru their website.
Ken
