You have been so helpful earlier in my task of identifying my channel balances with the correct top and shoe. I have replaced those parts and they work great, but now I need help replacing some top sash guides that I discovered were broken once I was replacing channel balances. I have several that are broken and nothing on your website matches up to what I have. They are 5/8" wide and only 1 3/4" long. They look shape wise like your alpine stepped sash guide
18-171, but that one is way to long. My step piece at the top is 13/32" wide, but it is only 5/8" long. The way it sits in my window, the normal 5/8" sash won't work as it will hit plastic at the top. Thank you.