Mary,
You may want to contact Jenny Gaylin, Tours Coordinator at The Freer and
Sackler Galleries. She conducted a "touch tour" for a group of visually
impaired visitors this past April. In fact, the Freer and Sackler's
Education Department has conducted a number of programs for audiences
with special needs. The phone number is 202/357-4880.
Also, The Smithsonian has a publication called "Part of Your Public is
Disabled" (or something like that). This could be a good resource.
Good Luck!
Mia Llarena