I'd throw the boxes away too.

FWIW, I bought an Apple //e years ago at a yard sale that was in its original boxes...they had been stored in a barn. The boxes looked OK from the outside but mice had built nests in them and the boxes smelled horrible (and were probably full of hantavirus too.) I threw them out, very reluctantly. The computer also smelled like mouse piss too and it got really bad once it was turned on for a while, even after bleaching everything. Real bummer