If they are all pre-82.... Keep them. 100% keep them. Unless you are moving 3-5 times in the next 5 years...then the hassle...maybe sell. But at least list on Craigslist or ebay and try to get $10 over face value in profit or 20% if we are talkibg about $100 facevalue or more.
RE: Did someone ask about stacking copper?