Thanks guys, I really appreciate your help! The left side of the action is engraved "charge 6 Drams Case 3" and the proof marks are black powder with .577 stamp. The rifle was made in 1895 for the Nizam of Hyderabad and was marked with a Gold 3 on the top lever. A good friend of mine has the records of all rifles taken from one of the Nizam's palaces. This rifle was listed along with rifles number 1 (10 bore Holland double rifle) and number 2 (.500 Holland double rifle). Here is an attemp of some pictures. The picture of the three rifles together are a 10 Bore Reilly double rifle, .577 Holland and a .450/.400 2 3/8 Cogswell and Harrison.