A hook that folds flat when not in use.
The base has a cutout in it for a small magnet from Ace Hardware or the like.
The hook has an internal cavity for a magnet as well. Pause the print at 6mm, put a drop of super glue in and then drop the magnet in. Then resume the print.
A nail with the head cut off is used as the pin.
I provided a hook without a logo.