Cranks are stripped. Wood casement windows . Arm is 9"to inside. Past curve. Looks like Manu was Wright. Windows were installed I 1974.

Hi there!

Thanks for reaching out to us. The 39-028E resembles what you have here. However, our operator's arm is 9-1/2" long when measured from the center of the gear to the center of the roller. We recommend you measure as shown below to see if this matches up with your old assembly. 

Dimensions for 39-028e