This is a Gibson made Kalamazoo KRB original 5-string banjo from the 1936-40 era.
I'll rate it in fair to good overall condition.
The tension hoop appears to be unplated brass. It has a mahogany neck, 3-ply (5/8") maple rim and maple (flat) resonator. It has no tone ring, just a bead turned on top of the wood rim. The tuners are the friction type, and are fully functional. It has a Remo head. The fretboard is a very fine piece of Brazilian rosewood. Frets look to be newer and have minimal wear showing. The resonator and neck both show a good bit of wear and tear from years of playing and enjoyment.
These banjos can be converted to a Mastertone configuration. It seems that most folks keep them original though, and just enjoy them for what they are. I'm told they also make good banjos for frailing.
The banjo will come in a hard case as pictured.