The shutter magnet brackets that came with our shutters only last a year or two before UV exposure causes them to crumble. PLA seems to last a lot longer in direct sunlight and weather (an outdoor experiment went eighteen months without any sign of degradation). I printed these in wood to kind of match our mahogany trim.

I reuse the magnets and metal plates from the broken ones: push the pin up into the bracket through the magnet / plate holes.

Note: the measurements on this are close to but probably not 100% to whatever standard spec is out there.