Crestline Casement

I have 2 Crestline casement windows that are about 30 years old. After all these years the window cranks on the right hand side of both of these windows have worn out and are now stripped and no longer work. The part number is 4-480-075. I need to know if I can get 2 of these and where. Thank you. I already checked with Menards and it seems they don't have it.