Barry Watzman wrote: On cleaning "copper" contacts (which may be gold plated): I would first try using a "magic rub" pencil eraser, rubbing it over the contacts. It is very important to use this specific brand, "Magic Rub", it's non-abrasive. These are popular and common and this brand of eraser is carried at all office supply stores (OfficeMax, Staples, Office Depot, etc.) On sanding plastic, DON'T. Instead use automotive rubbing or polishing compound and rub/buff with a soft cloth. (if you are going to paint, rubbing compound is the coarser product). It's possible these will leave a finish so smooth that you no longer need/want to paint. I am not familiar with the "magic rub" pencil eraser. Most pencil or so-called rubber erasers have a high sulpher content. They are especially hard on silver and copper. I've tried them on copper contacts and watched the color go from shiny new penny to forest green in a few days. If the connector is gold plated, you should not need to clean them. If you are having green, then the gold is a very thin plate, or an amalgam of copper and gold ( and possibly other metals) Have you tried a dremel tool with a dry polishing wheel - no solvent or compound? Use it lightly. This has worked wonders for me though it does take patience. I agree with Barry on the plastic. I would add to never use power equipment when sanding plastic. It always leaves a pattern that almost impossible to get rid off. A little elbow grease and lots of patience. Most rubbing compound is very coarse so run a test on a hidden surface before using. I've also used some astronomers grinding grits in water. These come in extremely fine grits and won't leave visible scratches. Used to buy them through Edmond or Fisher Scientific. Billy