Here's my newest addition to my bass collection.  This is a Bartell-made bass that may or may not be an early Black Widow.  Bartell made the earliest Black Widows for a short time and while this instrument is unquestionably a Bartell bass, it lacks the F-holes usually seen on Bartell basses.  The construction is still semi-hollowbody.  The knobs, if original, are the same knobs used on the Japanese-made Black Widows and on the Acoustic amplifiers.  Unfortunately, this one has had a rough life which included conversion to an 8-string and back.  It's also been refinished so there is no decal or other information anywhere.  It stands to reason that Bartell may have simply taken their standard bass model without the F-holes for Black Widow production.  I have no proof of this other than the Bartell Black Widow guitar seen in the 1970 Acoustic catalog which looks identical to their guitar models without the F-holes.