Sorry, those wedges aren't what I meant. My set didn't have the wedges (perhaps they are missing). What I'm talking about is the part that you stick between the yoke and the neck on the opposite end of the yoke that keeps the yoke from sliding back. In other words, the part you have to remove in order to slide the yoke off the tube, as shown below.
The yoke cover is OK. It had some white crystals on it which I've brushed/scraped off. Looks much better now.