Quaker double hung window
Hi- thanks for posting!
It's hard to tell while it is still installed in the window. Can we see a photo of it removed from the window along with some dimensions possibly? This will give us a better idea as to what replacement to recommend.
No, I'm afraid the cams are only sold inside of shoe housings.
Yep, the width and thickness are the two most important dimensions. Length doesn't matter so much, since there's plenty of room in the window for it.
Once you have your thickness, carefully go over our 15-188 and 15-178 to determine which is the better match. If neither match your thickness, let me know and we will try to find something better.