There's Margo Conover, who builds as a 1-woman shop in the under the Luna Cycles name, near Boulder Colorado. I wrote a "Hot Tubes" article (monthly profile of a framebuider) about her for Bicycle Guide magazine in the mid 1990s. I recall she built a nice steel frame with Henry James lugs. I haven't heard about her in a while, but just checked and she's around at lunacycles.com.
Alan Cote
Williston VT