Provided there are no stipulations or sensitivities about use for the piece (e.g. repatriation, etc), I would ask them to make a research appointment and then would be happy to show it to them. Our collections are held in the public trust, but that doesn't mean that they are best served being hidden away. As cultural and natural heritage institutions, we need to keep those channels of communication open with our communities, and that means inviting them in. Perhaps the visitor may have some information or knowledge to share about the piece.
You can always inform the visitor that the piece is in poor condition, but I personally don't think that should be a reason for saying no. It should be a demonstration that your institution is doing all it can to preserve the piece. They might end up supporting that, as well.
Dawn
Dawn Roberts | Director of Collections
The Chicago Academy of Sciences / Peggy Notebaert Nature Museum
2430 North Cannon Drive, Chicago, IL 60614 | www.naturemuseum.org
Collections Facility and Office
4001 N Ravenswood Avenue, suite 201, Chicago, IL 60613 | 773-755-5125
The Urban Gateway to Nature and Science