Ishapore, RFI, made MkIII's until the late 80's early 90's?? These are pretty nice rifles in general. hard to find one with wood that's in pristine condition. I have a 1963 RFI that has a great bore and metal finish, but the wood could be nicer.
Digging for info on the Lithgow I learned that Lithgow used a 50/50 mix of RLO and creosote to treat the wood. That explains the strange smell and feel this 41 Lithy has.
It appears unusual to find a Lithgow with this finish still intact. Most have been scrubbed with straight linseed oil and steel wool. This removes some of the 'blackness' for lack of a better term.