Hurd casement window crank handle--replacement needed

I need 1 replacement crank handle for a Hurd casement window, installed in 2000. This handle pushes onto the splined shaft of the operator, and has a spring clip to hold it on--no set screw. In the end view, you can see the splines and the spring fitting into the slot.
In the slide view, you can see my caliper reading 11/32 in the cylindrical part of the hole.
The splines' major diameter is about .320" or 21/64". The minor diameter is about .240 or 15/64".
Thanks for your help!