I use a electrolysis process to add copper to comm. Comm Sleeves don't give the same result as the electrolysis process. You need a pure copper high electrolysis sheet, distilled water, sulfuric acid, Copper Sulfate, battery, plastic tray and copper wire. It is a very dangerous process and should not be used by kids.
I don't know if you can do this in the States. Most people in Italy use this technique to recopper the Armature.
If you want more information about this process PM me and I will try to write a how to for this process.