dual arm crank for awning window

Hello! I saw a very helpful Swisco video about replacing this part. I have an awning window in my bathroom that will not close. When I would turn the crank, nothing would happen. It's difficult to determine what size dual arm crank I need to use. Also, when I took out the screen, I could see that many parts were in bad shape and I'm wondering if I need to do more than just replace the dual arm crank (and the handle too).

I measured the window itself as 16" high and 29" wide. There were some markings on the window. One seemed to be stamped on with ink and reads 7 25 85 8 MW (those last two letters are not entirely clear but the numbers are very clear). I can also see engraved behind it the following (but some letters are not entirely clear): CMHC 7687 (I think the first C could be a G; the 8 might be a B or a 6; I'm quite sure the rest are correct). Can you help me figure out what size I need? And do you see anything that might indicate that I need to do more than just replace it? Thank you! - Janet

Thanks, Casey. It does seem to look like the one I have.