Hi Yorkie,
When we bought our Swift Challenger earlier in the year I asked the dealer to fit them as part of the package of things I wanted done to the van. They called them "corner plates" and charged us £20 to supply and fit the pair of them. They are very useful for finding the winding nuts without having to bend down so far; but I was surprised that they were called corner plates. I guess they would fit similar AlKo chassis.
Cheers
Mike A