Made this for my colleague some other day for organising his personal toolbox.
The STL's are based on a design similar to a typical off-the-shelf Magnetic Wrench Organiser.
Original version suitable for placing rectangular magnetic.
To avoid supports, split version is made. (and per my colleagues request, circular hole was used instead of rectangular hold for holding circular magnet).
STL made from sketchup web.
The author hasn't provided the model origin yet.