Boston, Massachusetts. $5 1882 Brown Back. Fr. 467. The Mechanics NB. Charter #932. PMG Very Fine 20.A solid example of one of Bostons toughest banks. Just five notes are listed in the current census according to Track & Price. This is the only Brown Back example known, and the first time it has been offered for public auction. Seen with large margins all around with good signatures, and overall eye appeal.