I have a bunch of 1922 and 1923 Peace dollars, probably 75 in all. They are mostly AU probably 50-55 or so. Not bad but they're not going to win any prizes. I would like to sell them but the problem is that they're mostly quite dirty. Not scratched or anything horrible, just grimy and dirty. I know I shouldn't clean them, but I don't think I could sell them for much the way they are since they look so bad. Any suggestions?