I own a .275 Rigby and mine is a number 2 High Velocity. I don't have the gun in hand but I recall it has .275 Rigby, 140gr high velocity on the reciever ring with the Sackville address on the bbl. Interesting bit above about the number stamped on the bottom plate as mine has a silver number 1 engraved there. When I visited Paul Roberts I looked at the ledger book, found my rifle, and the number one on the bottom plate stood for (1 of 2 guns; ie; matched pair) as per Roberts. In the ledger my rifle is cross referenced with its pair (which is marked number 2 on the bottom plate). I don't believe the markings on the bottom plate stand for the type 1 or type 2 rifle. There was also a number 3 rifle that they built in the 30's which had a shorter bbl and stock. BTW- My .275 HV was owned by Lord Zetland, Secretary of State to India, sold in 1932.