Pre war gibson mastertone banjo dating
The RB-75 (Crowe) had the flying eagle pattern, the RB-4 had the flying eagle pattern, the Earl Scruggs Model had hearts and flowers (also had an ebony fret board).
The Granada was available with flying eagle or hearts and flowers.
Also the resonators were sunburst with concentric rings.
After this period Gibson reverted back to the two-piece flange banjo that they had used prior to 1930.
Not only because of the many shapes and styles, but because of the company's rich history. and Foreign patent stamps, this Virzi Tone Producer was removed only after opening-up the mandolin.
The models during this time frame include the RB-250, RB-3, RB-75 (JD Crowe), The Earl Scruggs Standard, RB-4, Granada, and the RB-7, RB-12, & RB-18, which are top tension models.
Here are some more pics: The Gibson Mastertones of the 1950's were constructed with about the same specifications and quality levels of the 1930's and 1940's.
Unfortunately, they discontinued the Flat Head Tone Ring by the end of the 40's.
This was also the beginning of the Bowtie banjos, which lasted until 1969, but with a peg head change in 1968.
The Bowtie banjos were available in arch top or flat head, and some of the flat head tone rings had 20 holes and some had 19 holes.