Crank for our bathroom window

Hello,
I would sure appreciate any help you could give me on fixing the crank for our bathroom window.

Unfortunately the handle broke off a long time ago, and I didn't know where to look for help.
Fortunately I stumbled across your company and hope you'll be able to suggest something.

The overall crank mechanism is 4 3/4" long, and 1 1/2" wide.
The window is about 16" tall and 29" wide.


Please let me know what you might suggest.
Thank you,
Paul