Gibson TB-3 Mastertone #8090-24
The banjo pictured above is a TB-3 with a ball-bearing tone ring and dates from 1925, the first year of Mastertone production. It conforms to standard catalog specifications for the style 3 of the time with maple neck and resonator, single white binding on the fingerboard and and back edge of the resonator, two-piece flange, nickel plating, Presto tailpiece, fiddle-shaped peghead, diamonds and squares inlay, and Brazilian rosewood fingerboard. This banjo has been converted to five-string with the addition of a neck by an unknown maker.
Mastertones from 1925 are readily indentifiable by two features unique to that year: The ball-bearing tone ring has holes on the outside skirt and the Mastertone logo appears on the peghead inlaid in small individual letters rather than on the fingerboard engraved in a mother of pearl block. This example is particularly interesting as the "N" in "Mastertone" was inlaid backward! A Gibson catalog from the 1930s touts the all-seeing eyes of the factory inspectors--they were obviously not on duty the day this banjo came off the line.