The Klute DVD has a great contemporaneous behind-the-scenes documentary included in the special features entitled "Klute: A Background for Suspense" with great quotes from Pakula and Willis (also Sutherland and Fonda).

Parts of Klute were also filmed at Filmways Studios in Harlem (possibly 245 E 127 St) where the Godfather was also filmed. It would be interesting to find out what else from my list was shot here, as I'm sure imdb info on this is incomplete.

Also found an article from New York Magazine, March 16, 1992 (pp42-?) that has some things about Sonny Grosso's film and television work.