Leslie Hindman Auctioneers
Located in Chicago, Illinois, Leslie Hindman Auctioneers is an auction house that was founded in 1962. The auction house was subsequently sold to Sotheby's in 1997, and then reopened in 2003. The company participates in auctions ranging from contemporary paintings and fine jewelry to French furniture and rare books and manuscripts.
After Sultry Night was at Grinnell College, the work was sold by Leslie Hindman Auction in Chicago to Grinnell donors Mr. and Mrs. James Jackson (now deceased) in 1979.
According to Live Auctioneers, the estimate bid was $3,000-$5,000 and the starting bid was set at $1,500. It is unknown what the final sale price was.
Sources:
http://www.lesliehindman.com/
Kay Wilson, Grinnell College Archives and Special Collections