Decided to buy a set of used oem F20C (PCX) pistons for a custom H series build. As everyone knows FRM compatible pistons are needed for these engines. Got ripped off, the pistons have the pictured wear and look unusable

Can anyone say what caused the coating to come off like that? Ive never seen this before on oem prelude pistons. Normal wear?? Perhaps spun bearing/ overheated? These pistons new from Honda are rather expensive, so Im bummed.