Take it to the Fridge!
A classic once-off 'works-for-me' design using the magnets from a dead Seagate Hawk (ST31230N, c. 1995)
Only works if there are threaded holes on 1" centres on the magnet yoke. You can also reuse some of the Torx screws from the hard drive itself including the long screws + standoffs that hold the magnet yoke together.
BTW, a stepped plastic furniture shim makes a great tool to pry these beefy magnets apart ...
You probably want to set the top/bottom layers to very thick (say 2 mm) to ensure the screw tab is solid. These are very strong magnets!
… the usual way: start off with a big block and carve away everything that doesn't look like a fridge magnet grip.