Gibson PB-4 Mastertone #9525-6
The style 4 inspired some enthusiastic prose from Gibson in its 1931 catalog:
"Rich, radiant beauty is the key-note of this instrument both in tone and appearance. It is the materialization of the dreams of the most distinguished artist, yet it is not too costly. . . The finish is a beautiful, compelling, Burl Walnut--hand-rubbed to the point of sparkling iridescence. All metal parts Chromium plated, the best wearing plate known to science".
The majority of 1930s style 4 banjos were tenors and came with forty-hole archtop tone rings. Circa 1929, however, Gibson started equipping some Mastertone banjos, typically plectrums and five-strings, with the new flathead tone ring which, according to Gibson catalogs of the period, provided greater "twang and sweetness" for plectrum and five-string tunings. #9525-6 (see Gibson banjo serial numbers vs. factory order numbers) is one such banjo and has an original high-profile twenty-hole flathead tone ring.
#9525-6 has now been converted to five-string with a neck by Steve Huber and a set of prewar Grover two-band tuners with large Catalin buttons:
Photos courtesy of an anonymous collector, who can be heard putting #9525-6 through its paces with his original composition "Nicomede".