Window crank

I live in a 1959 Fairmeadow Eichler. What was once a laundry room I think still has the original steel framed (Arcadia window?). It's a standard sized casment consisting of two opening windows either side of a fixed pane.

The opening panes have a closing latch and a rotating opening crank. This devices is surface mounted and secured by two screws. One of the crank units is missing and I need to replace it.

Does anyone know where I might go? I've found a image of something similar via Google but no suppliers despite much clicking around. I went to the Arcadia website but that was an exercise in frustration.

I have the image handy if anyone wanted to email me directly at paulr1234 At yahoo DOT com

Thanks :)