Conn Unknown Model BBb Bass

Conn Unknown Model BBb Bass 1924

Date: 1924. Owned by Tim Seaman

Here is a bit of a mystery. This is a 1924 Conn BBb bass. As the picture shows, front facing bell with 4 front action valves. Bore size is about 0.735", which is a #10½ bore. Bell size is 19¾'" and the instrument is 41" tall. The bass experts agree it probably isn't an 82J. Anyone know what model this is? There was a discussion on TubeNet about this instrument.