I'm pretty sure it is plastic if I remember correctly. In my opinion it should not be peeling. That said there is a drain hole for water that would get into/under the wind area. If you were to work on it my advice is use a magnifying visor, fine tweezers and some utlra fine sand paper (what is it 400 grit? I forget now) I get my things at a jewelry supply place. If you did peel and sand down plastic, sealing it up would be the most important, but it shouldn't have done this in the first place. Would something like a rubbing compound work better? Is there a mild scrub for kitchen or shop use? Sanding with water will smooth the finish out too I think.

You know what go out and tap it some (with something a key maybe) you will hear if it is plastic or metal, it sure looks like metal; first because of the things bolted to it and second why would a plastic piece be painted? Wouldn't the color just be in the plastic to begin with? It looks like paint peeling off of metal to me.

I'm going to run for a public office, I just gave two opinions!