From my research, it looks like a Slingerland Maybell plectrum, A Type. I'm not really sure, I don't know ANYTHING about banjos, but identifying this family heirloom should probably help me fix it up and play it.
Specs:
11 1/8" head, 4 strings, 19 frets, 13 3/8" resonator with hand-painted design on back. Missing arm rest and two strings. Plays loudly with the original strings, still need to restring it.