Genevieve / The Man Who Haunted Himself / Crossplot
I can confirm at least twenty locations from the three above films plus the mews and market street used in The Italian Job. I've been a location hunter for about 20 years now (primarily on 60s/70s British TV series such as The Saint, The Avengers, The Persuaders!, etc) and have found a lot (used to live in London!).
Check out www.theavengers.tv then A Guide to Avengerland.
Will send you a load of location info and images in the next few weeks.