Peter:
Those hooks can be saved still. Prepare a citric acid solution, and Immerse them for 24 hours. Then use a soft copper brush, Immerse them for another day, and then they will be ready for a thin layer of sprayed paint.
Citric acid can be bought in amazon, it comes as a powder or crystals. It’s easy to solvent with water. Very effective.
Best regards
L.peterssen