Glue four rubber feet slightly offset under each of the base plates.
When you place the base plates on top of each other, the feet should not touch.
The keyboard cases and also the wrist rests have magnets in the bottoms. Thus, the keyboard halves stick to each other when you put the bottoms together.
If the parts stick together you can stow the keyboard away or use it as an an eye-catcher.
You can also use the magnets to attach the keyboard to a magnetic surface. Here is an early prototype, for which I made a wooden board. Magnets are embedded in the plate to hold the keyboard parts.
In order for the keyboard halves to stick together, you must align the magnets accordingly. For example, in the keyboard housing and the wrist rest on the left side, the north pole of the magnets points upwards and in the other half, downwards.
Inserting magnets into the base plates
Use superglue to glue the magnets into the holes. It may help if you hold the remaining magnets from the bottom against the plate.
After the glue has dried, put an additional magnet onto each one on top.
Then put insulating tape over the magnets.
Screwing the base plates
Screw the base plates under the keyboard housings using 13 x M2 x 5 mm screws.