Seeking replacement hardware for awning window.

I'm trying to replace the worn-out window cranks in two awning windows. They are in a sunroom built by a company called Four Seasons Design & Remodeling Centers. The only markings on them that I can find are the front facia that says Four Seasons Green Houses and the arms are stamped with a respective L and R on the two separate arms. I believe this designates the left and right arm. Any help would be greatly appreciated.

Elijah