Between tearing out those concrete beams and hauling all kinds of stuff, the drawbar suffered some wear.
Lifting that oversized trailer too high finally bent the relatively thin support bars to the top link, so now its difficult to hook up the smaller trailers.
A replacement drawbar just arrived. These are a good deal at €68 for that much steel, but come with somewhat thin support bars.
Now I can recycle the bent one with its pins for making some pallet forks.