After Watching Mr.Puzzles video on youtube and needing a money gift box for a friend I decided to make this seemingly Impossible Dovetail Puzzle Box and it worked really well and it is a really fun print. The "bottom V.2" has a much larger storage compartment.
Also if you don't want it to be locking or don't have the parts to do so you can still print the puzzle as it is.

UPDATE!! I have added two new files that fix a problem where when opening the box the contents would spill out due to the location of the storage space. Both files are labeled at the end with "Fixed" and as a bonus the storage space is even bigger than before, it also has space for a optional second magnet that holds the ball while unlocked. Happy Printing

To solve the puzzle you just need to hold the puzzle with the top side, in my case the red side, up and hit it downwards with a bit of force this releases the steel ball from the magnet and then it will slide at a 45-degree angle.

Print instructions

0.2mm works for me, everything else is up to you

To assemble the locking portion just press fit a 6mm(Diameter) by 4mm(Hight) magnet into the hole in the bottom of the box and then a 15mm steel ball should fit in the larger hole and act as your locking mechanism.