Summary

I own this box with wood, but can't remember where to buy. So I printed one to have a gift for puzzle fans in the familly. you need 2 neodym magnets 5 x 1mm (NOT stronger - that will not work) and a steel ball 9.5mm
(I used 9.5mm steel balls/marbles because I had a lot for the The 3D Printed Marble Machine #3 from Tulio

P.S. I found a solution video at youtube - search for "The Impossible Dove Tail Box "
I added a part2 with a hole for money or a little gift