I bought a few coins from
ebay. As the buyer used plastic tape for packaging (tape on the coin, I put the coin in the case after removing the tape), striped toning pattern could be seen on the back side of the coins. (See pictures).
The area affected by the tape is darker. (The buyer only taped the top and bottom of the coin, thus the striped area is not affected by the tape, that's why it has a lighter toning)


In this case, is there any way which can get rid of the striped toning pattern?
1. Using acetone? (I dunno whether it really works after reading earlier posts)
2. Tape the unaffected area, thus darken the whole back of the coin
3. Leave the coin alone, and let nature to oxidize the affected area?
Thank you very much.