I saw something like this a while back, wanted to buy one but I couldn’t
find it anywhere, so I made one inspired by that picture. I made it out of 1/2" plywood and I used 1" drywall screws.
Make sure to countersink all the holes for the screws.
Next, slide the notched piece through
the gapped one and drill holes on the top and bottom 1/2" from the edges and countersink those too.
Finally attach the wall hanging piece with 2 more screws and thats it, screw it to the wall and start hanging your watches. Enjoy!