A longer thumb rest for Yamaha YCL 221-II Bass Clarinet

Hello, I recently bought a Yamaha YCL 211 II bass clarinet and I'm very content . The only thing that is a bit strange is the placement of the thumb rest. For me it's just to low. There would be space to adjust it to a higher position, but the actual thumb rest doesn't allow for a lot of upward adjustment.
The thumb rest looks like your average tenor sax plastic thumb rest; I wonder whether there is a longer replacement part that would allow for more upward adjustment?

Any suggestions very much appreciated.

best
Robert