What's the vintage?
I know almost nothing about these but is it possibly a refinish by an arsenal, or a war time finish? I've seen what looks like that before, I just can't place where..... Sorry it doesn't help much. I will say I like the character the imperfections give these old war horses.
With out having it in my hands, , but I may be wrong but I think some one did that finish, most of them I have seen where black and was a type epoxy paint job. the One I have is got a black finish Just my 5 cents jj
Here are some pics of my 1943 Savage Arms Enfield No.4 MkI*. Note the finish on it. My 1942 Lithgow S.M.L.E. No.1 MkIII* has the same finish.
It looks like someone painted the one you have. I would try to have someone remove that finish very carefully. There should be the original finish underneath.