I think Fisheye plays a Goldtone. It sounds like a banjo. Slats plays a banjo about 100 years old with a thick vellum skin, and apart from being untunable (yes, it's a banjo) it has, as Peggy Seeger might have said, a nice plunky sound.

None sound anything like as nice as that guitar/mandolin-bodied banjo-necked thing that Joe Stead uses built by Peter Abnett.