I can't identify the window manufacturer or find a part number anywhere. This crank connects via a pin, there is no bore or spline. Thanks
Tom from SWISCO responded:
June 19, 2018
It's tough to say what you have. There would have to be a spline, otherwise there'd be no way for it to interact with the operator. I wonder if you have some kind of combination handle/cover like our 39-375 and 39-376. Look these over and let me know what you think.