Stainless steel mudguard is dis-coloured (near battery)

[Smartv11]

The rear mudguard (or fender.....), is dull and discoloured near the battery, i assume acid vapours??. How can i remove this dullness???

also, my chainguared has rust marks, I thought it was stainless as well?

the bike is a SF with original parts

Paul

 

[Grant]

Chainguard is chromed steel.
You might be lucky and be able to have the discolouration in the rear mudguard polished out but it would likely need a heavy duty polisher.