Broken bay window crank

Thanks for posting. We may be able to help, but we have to see the entire window operator, including the split-arm that juts out the back of that gear box and pushes and pulls the window sash. A bird's eye view, with either the assembly removed from the window or with the window open for a clear photo, would be best. We will do our best to help you from there. 

Thanks! My top recommendation would be the 39-187. I think this is just the party ou need, but review its dimensions and see how well they compare.

Dimensions for 39-187