This is one of the strangest Bartells I’ve seen.  This is a customized Hohner fretless but it appears the modifications are factory original to the bass.  The controls are on the upper bass side rather the lower treble side and there’s no evidence of a bass side F-hole.  The leather arm pad is also unusual as is the binding on the front and back of the body and on the headstock.  The tailpiece shows evidence of having been moved once or twice and check out the output jack just below the tailpiece!  I just barely missed owning this one.