If you are thinking of selling them, don't do any cleaning. Since you are going to a coin show, I would let the experts there tell you what they think after they review/appraise them. If the ones you think need cleaning turn out to be nominally worthless (I don't know what worthless to you would be) then I would probably clean them. There are a lot of smart people here who can tell you the least abusive way of cleaning them. Warm filtered or distilled water and a toothpick with some mild detergent might be Ok.
Nice finds, but sorry you had to get them the way you did.