five-string RB-1 is quite unusual in that
it features the rare "Coke bottle" peghead shape, the diamonds and squares inlay
pattern normally seen on style 3 banjos
from the 1920s, and a Mastertone label inside the rim even though
style 1 was a sub-Mastertone model.
At least one other banjo from this lot,
banjo serial numbers vs. factory order numbers), is also known to have a Mastertone label although its inlay
pattern is the conventional style 1
fleur-de-lis design. Two other examples from lot 9527 are known with the
diamonds and squares pattern as seen here.