i don't think they can off load them without getting caught. Our chipping community is a good one. Be more patient than the crooks.....they will make that 1 mistake trying to sell the chips.
I would go on the ChipGuide and print out what you think was in the collection and pass it around to some of the businesses in your area that deal with collectibles.
Also check craigslist regularly. These people are most likely not that bright. I hope it all works out for the best.