Did they use the old house of the Walton's for the Dragonfly Inn on the Gilmore Girls?

No, the Dragonfly Inn in "Gilmore Girls" was not filmed at the old house of the Waltons. The exterior of the Dragonfly Inn was actually shot at a different location, specifically at the historic "The Dragonfly Inn" building located in California. The Waltons' house was a separate set used for the show "The Waltons," which is distinct from the Gilmore Girls production.