http://www.amazon.com/Yellow-Jacket...&qid=1360638847&sr=8-3&keywords=sulfer+powder work it into a cloth, maybe use a little oil and work up a paste, and apply it to the coin. play with it a bit until you like result. I don't know the specifics, but I know a lot of the large cent collectors use some kind of a sulfur compound and get good results re toning a harshly cleaned coin. To those screaming 'Coin Dr.' it's only doctoring if you try to pass the coin off as not altered. I have a lot of recolored large cents, all of which were bought knowing they were recolored. I even have some in NGC and PCGS holders if it makes you feel any better. I would personally prefer a recolored old copper to a harshly cleaned copper, so it's preference. To say you should never do it is being ridiculous, you should never do it and pass the coin off as original. I will only add that sulfur is one of the compounds that tones copper, all this is doing is speeding up a natural the process, not like filling with putty and coloring on gold coins.