[raymo]

Have a look at the Skywatcher one that is in the Bintel online
catalogue. It comes with two different mounting brackets, and has a flexible coupling should it be needed.[my scope didn't need it]. I would think if neither bracket was right for your focuser, it wouldn't be hard to make one. Incidentally, it connects
directly to the focuser's shaft, not to a knob. Anyway, worth a look at $89.95 + postage. I have no connection to Bintel.
raymo