I made this case using the "Tool box Parametric" design by Yanev.
The hardware needed is (6 qty.) M3 x 30 socket head screws.
The magnets that fit the inserts are (3 qty.) 6mm x 3mm
The author remixed this model.
I changed the parametric dimensions that the design allows in fusion 360 and then modeled an insert that fits inside with a cutout for the calipers with magnet inserts to hold them securely.