Channel guide

I measured this guide as you say to do on your website it came to 21" and is 1/2 width. There is a stamp on it marked 21 c bsi. I cannot find any manufacture or other markings on window. The spring busted on the other guide i would like to replace both. The house was built in 1987 if it helps. I also need a 5/8 sash guide. There is no slot for the hook in the channel guide to catch at bottom of window frame. Do I need to cut a slot in window frame for it to work properly. How do you replace the take out clips at top of window frame there intact but old. I was thinking of replacing those as well. I will b calling Monday to order. Thank you for your time.

By the way my name is Steve and I have more pics in multiple emails sorry.