Acquired what I believe is a #15 Aristocrat a few weeks ago which, after a bit of a light clean, looked in good condition. However after two or three uses, black marks have appeared on the Rhodium plated handle on both sides where you would grip the razor. I am suspicious that these maybe wear marks which have been "doctored" by the seller, or is Rhodium prone to marking like this. If so how can I remove said marks? Light cleaning with a toothbrush and paste have had no effect
Rhodium, due to the high cost, is usually applied as a VERY thin coat. If done properly (often time in 2 coats), the durability is greatly enhanced. Since the marks you describe appear on the handle, I imagine you're seeing areas (darker) where the plating has been worn. No amount of cleaning will remove them. Not seeing pictures, however, this is all speculation.
I am not an expert but i have worked a little bit with DE's restorations For sure the photo's will help a lot for a better conclusion.
Having looked closer at these marks tonight through a jewellers loupe, I can in fact see the coppery base underneath these marks, and it appears the rhodium is worn through. Ah well, off to the restorers it goes.It slipped under the radar anyway on ebay, so nothing lost.