Maybe a slight amount of oxidation, which is technically a type of corrosion but it looks more like residual offgasing from the plastic protective sheet. Take a solvent and see if it wipes off. Otherwise, a light polishing as already suggested will clean it right up.
Smart People do Stupid things all the time. I know, I've seen me do'em.
RV6 - Builder/Flying
Fiat G.46 -(restoration in progress, if I have enough life left in me)
RV1 - Proud Pilot.