I'm attaching a photo of and East Germany produced Marma Tenor/Plectrum banjo. I'm calling it a Tenor/Plectrum because it has 20 frets, a type of banjo introduced by Gibson back in the late 1920's.
I feel like some of the construction elements are unusual so I thought I would show it to folks here on the hangout who might be interested in different ideas.
First, like a lot of European fretted instruments it has a zero fret. It's an archtop and utilizes a plastic tone ring that resembles wide binding. The rim is made up of 4 pieces of timber, two narrow (5/8") semi-circle pieces of timber glued on top of 2 wider (1 3/8") semi-circle pieces of timber. The rim components are joined at the neck by some sort of lap joint (rabbet) and at the tailpiece end they are joined by a thin piece if timber that is glued into slots cut in the rim components. The guitar tuners aren't original and neither is the tailpiece. There is evidence that it originally had a resonator on it but, when I got it from a friend (haystack) Jimmy Bynum, it did not have a resonator.
Today, when I got tired of practicing, I decided to set it up and see how it sounds and plays. I tightened the head up to about the same tension as my flathead 5 strings which is a bit like stretching a gnats behind over a rain barrel. In other words....real tight.
It's strung with Irish tenor strings so I tuned it GDAE. This little banjo is extremely responsive with nice focus and clarity, decent tone & very LOUD. Something I wouldn't have expected since it has the plastic tone ring. I've attached a composite photo of the banjo for your inspection & comments.