Thanks for posting. We may be able to help, but I'd like to see the entire mechanism, including the link arm(s) that push and pull the window. A bird's eye view, with the mechanism and arms in view, would be best. We will do our best to assist you from there.
That's a huge help, thanks! Please start by looking at our 39-031 and 39-032. I think these operators may be what you want, but review our arm dimensions below to verify that they line up. That will be the determining factor. Note that you'll want to disconnect your arms from the sash before you measure, otherwise you won't get an accurate read.
