The C&C 35 that I recently re-rigged also had some corrosion issues on the spreaders.
As you can see the aluminum spreader tips were not getting along with the stainless steel clevis pin.
I removed the spreaders and inspected them for any structural issues.
I then sanded the problem areas and prepped them for paint.
Four coats of zinc primer, and four coats of white top coat and they were like new again.
Final picture of spreaders re-installed with new rigging.