Caring and Displaying My Collection

Greetings from Boston!  So: many years ago my daughter started me a collection of cookie cutters.  Naturally, I've used them and always stuck them in a paper bag in a cabinet when not in use.  They look kind of ucky now (little black spots, rust) and I was wondering what the best way to clean them might be.  Also, I'd like to display them; any ideas? THANKS!!!!