Many thanks to Chris S. for letting me review this very special Hard Rubber Conn clarinet! Note the very special antique Conn logo, much different than the modern Conn logo. Note also that there is a charming mistake on the bell. It was stamped twice, front and back, with “Made By.”
It has no serial number. Unfortunately, the clarinet is High Pitch!
The main unusual thing with this clarinet is the fantastic special keywork on the right hand joint. There is a unique articulated C#/G# mechanism. (I'll drop the 12th-above upper register notes and just speak of the lower register notes from here on.) The C# key is the plateau-shaped key, the first one on the of right hand joint. (Your first finger doesn't go there, of course, so it is not really a plateau key.) There are two ways to raise the C# key, and both are dual function keys. One is with the left-most, low F# pinkie key. Then, next to the low E key, there is a special little lever which raises the C#, but also lowers two pads to play low F. So there is both a left and right pinkie way to play low F! So there are two ways to play a C#, but neither of them will raise the C# key if any of the three rings below are depressed. Note that the low E key also has an extension, giving the player two places to depress the key. If moving between low E and F#, it is much easier to use the rolers. But if moving between the left low F key and the low E key, then the low E extension is easier to slide to.
Because of the combination of unusual articulated key work plus a high pitch hard rubber clarinet, this is an interesting collector's item. There could not have been many made, and surely this would be one of very few left in existence.