Let's take apart a prewar flathead Mastertone!
Most owners of original prewar flathead Mastertones are understandably reluctant
to take them apart. . . once the banjo has settled in, why take chances by
messing with it? I recently had the opportunity, with my good friend Mark
Bramlett of Banjo.com, to disassemble and clean up
PB-3 #66-2/#EA-5347, which
had been under a bed and unplayed since the mid-1970s. I thought you might
like to take a look:
It looked as if it had
been a long time, if ever, since the neck had been removed.
The flange is remarkably flat, not showing even the normal
slight pulling up on either side of the neck cutout.
The neck heel shows no signs of alteration. The
factory order number is stamped on the back of the peghead, so there was no need
to write it on the heel as had been done in earlier years. The original
fingerboard shows the correct prewar thickness of 1/8".
The tone-ring-to-rim fit on this banjo is what many regard
as perfect. The rim and ring assembly could be inverted on the workbench
and picked up by the rim with the tone ring remaining in place; one shake was
all that was needed for the tone ring to fall off onto the (well-padded)
workbench.
The positioning of the twenty tone-ring holes relative to
the rim appears to have been totally random. While this banjo has a hole
directly above the "m" in "Mastertone", littermate
#66-5 has holes over the "b"
in "Gibson" and the "e" in "Mastertone".
In common with many
players of his generation, Earl Collins
(June 24, 1915--May 18, 1988)
safeguarded his banjo by marking it with his name in an inconspicuous place.
While some later prewar tone rings were buffed on the
inside face as well as the outside face, this ring retains the machining marks
on its inner surface. The edges of the holes have noticeable burrs, in
contrast to the more finely-done holes in most modern tone rings.
The top of the tone ring exhibits some pitting and loss of
the nickel plating, likely due to moisture from newly-installed calfskin heads
early in the banjo's life.

Machining marks and burrs at the edges of the holes are
also visible inside the tone ring. This ring weighs three pounds, two
ounces.
The presence of stain on top of the rim indicates that this rim was intended from the start for a flathead tone ring, rather than originally being made for an archtop ring and then modified at the factory.
The Mastertone label was applied slightly lower, as was
often done on top-tensions, with the lower part of the label curving around the
bottom of the rim.
The top of the rim appears nice and tight, with no evidence of voids or delaminations.
Keeping all the hooks and nuts in order may be a little on the compulsive side, but why not?
With a new head installed and everything cleaned and back together, the banjo is ready to wake up after its long "hibernation".