Gibson TB-1 #9486-2
This banjo dates to 1929 (see Gibson banjo serial numbers vs. factory order numbers) and is from one of the first lots of style 1 tenor banjos to be built in the then-new design featuring a "pot metal" flange and stretcher band and fiddle-shaped peghead with fleur-de-lis inlays. #9486-2 is a catalog standard example with the exception of a missing armrest, which is most likely the way this banjo left the factory. Most style 1 banjos of the 1930s had only three resonator screws, but some were produced with four screws and on these the added screw is typically positioned symmetrically in relation to the other three, rather than being displaced one bracket to be out of the way of the armrest attachment hardware as was usually done on four-screw models. This positioning of the fourth resonator screw apparently led Gibson to leave off the armrest on a number of these style 1 banjos.
The earliest cast metal flanges and stretcher bands produced for Gibson by the Doehler Die Casting Company were plagued by a type of intergranular corrosion known as "zinc pest"; #9486-2 has unfortunately been affected by zinc pest and shows warping and cracking of the flange and extensive disintegration of the stretcher band.
Photos courtesy of E.D. Marshall Jewelers.