Remove toggle and foam, grab top and bottom of plastic plate, wiggle and pull towards you... Pop! Easily slid back onto the track right next to the wall. Great for quick access to what you put in there - like lunch on an overnight or a light drybag.
Hmm could be a scrap, could be a bow-piece added on to where the front wall was sliced off. We had some short-cut walls and went back to retro-fit the very tip of the bow but that piece will look like a smaller version of the bulkhead foam... bow profile shaped. Message or email me with extra details if you like. I can't think of any piece that's crescent moon shaped and supposed to be in there. My first name at Jacksonkayak dott com.