Inoperable Jalousie Window

I am a Handyman, trying to fix this window for my customer. There are no markings on the window and, it is not frozen or painted shut. It looks to be a standard window with standard parts. The Tee handle spline is stripped out but, the window cannot be cranked open using vise grips on the operator spline. I am assuming that we can replace the operator and any other required parts with your assistance.