Stains?

My Ranger Tech, which has been replated a few months ago, today I noticed on the head on one of the doors there are a couple small spots. They are brownish and look like droplets of something. I tried with some Simple Green, Dishwashing soap and a soft toothbrush, no luck. I think they are water stains, but are water stains dark? I fear they might be droplets of bathroom cleaner or something that splashed on it during cleaning the bathroom, hope the plating isn't ruined. My last option would be perhaps a polisher?

Try mass is it? I read that's good for most things like that.