The story of "Autumnglo," "Walnut," and "Brown" is confusing and apparently changed at least a few times back in the '70s and '80s. Don't know that there was ever a bass in that "Brown" matte finish, but for a while "Autumnglo" was made with a semimatte clear coat while the same color with a gloss coat was considered "Walnut." The "Brown" matte overall finish appears to have been applied to a few models of guitars, but not to any basses that I've seen. The overall, glossy, non-burst Walnut ones that I've seen so far appear to be from '74 and early '75. Much more in the book.