A handy person from New Fairfield, Connecticut says:
August 28, 2017
Hello, this handle worked with our vintage awning windows. We just ordered (4) Part #39-076 Center Gear Operators. The old units were stripped out. The splines on the handle are pretty rounded too. We can replace the bit as well if that is an option. Your Center Gear Operator's dimensions are exactly like ours. What drives would fit? Thank you very much!
Casey from SWISCO responded:
September 1, 2017
The only part available for this older awning window is the 39-076 center gear operator. I believe it was originally made by Stanley. No other parts are available, unfortunately. I hope that helps.