My latest Bartell bass is an oddity.  What we have here is what appears to be a standard Bartell bass, but without any f-holes.  The knobs appear to be the same as those found on amplifiers made by the Acoustic Control Corp.  Unfortunately, it’s had a rough life in the past (including having been modified to an 8-string bass and back to 4 strings) and has been refinished, leaving no labels anywhere to identify it.  This may very well be an early Acoustic Black Widow bass.