looks to be russet [assuming the pic and my monitor are in sync], treated to have a mottled look. by the drape and smoothness of the hide, i would guess a type of lambskin. so, kumite, why not introduce yer self to mob.
The mob are the members here!
Welcome Kumite
The members of this forum are very knowledgeable and can answer many of your questions regarding vintage jackets.
Looking forward to hearing more from you in the future.