Thanks for all the input guys; I hadn't considered the auction-end ramifications but have decided to end it. Considering that there is a full week left of the auction, I don't think people will have invested so much time and hope into the auction as to warrant being justifiably upset. If it were further along, it would have been a harder decision, I think. I see both sides, certainly but I think this is a reasonable approach.
Definitely the right choice to end it and re-list with the appropriate details. Any chance you can message the bidders and let them know why/to look out for a re-list? Maybe even PM them after the re-list with an apology, reason, and link to new auction?