This piece is so great that it deserved to be opened.
I've detached the link to model a special terminal with a 5mm hole to a neodimium magnet. I've used 5x8mm neodimium for maximum strenght, but you can use whatever.

The terminal is self centering, very nice result !

Great design, must be fabricated !

Cheers,
Paulo

I've rotated 45 degrees so it can be printed in any 200x200 printer.

Put some superglue in the magnets. Take care with polarity before gluing.