The WORKING keel-box, actually. Finally.
After all sorts of troubles, and after throwing away the first failed attempt, we now have a box that works. The keel goes up and down with a nice snug fit while only taking a about one or two hundred kilos to pull. This is less than it sounds, the lifting mechanism can overcome up to a ton of friction.
Just look at the kind of acrobatics that was needed for this work :-) !