I just finished work on a Uebel low c bass clarinet. This is the first time I’ve worked on one - let alone seen one in person - and I'm very impressed with it overall.
This particular model was made in East Germany in the late 70s, and has quite a few notable design features which make it stand out from other bass clarinets. First and foremost, it has a smaller bore diameter and a wooden bell, which give it a very unique tone; it also comes with an insert for the neck, to allow the player to use either a standard bass clarinet mouthpiece, or one of the two provided Uebel mouthpieces which both have a smaller tenon diameter.
Is this still a Bb bass clarinet? I own an Ubel basset horn which is F. Looks very similar with straight wooden bell and small mouthpiece like a Bb clarinet.