20 years ago I made Christmas tree ornaments using 3/4 in. wide scotch tape to 25 chips only one side, using a small paper clip as a hanger. This was before I joining the club and had no knowledge about chips. I was cleaning the garage and found a old box of Christmas ornaments, in the bottom was a small box full of these chips, I had forgotten what I did, So took off the scotch tape, and no damage to the chips, but on some a sticky residual remained, especially the coin in center chips. Some very nice old Nv. chips. Any suggestions what can I use to remove?