name='Anthony McKay']After recently identifying the airports seen in this episode we'd like to clear up the rest. The episode was filmed around 1958.
Unknown 2 - Wilson and Sewell arrive at the flat where Doctor Stephens is hiding, number 10 Harrow Lane. Later Doctor Peter Brady arrives in his Austin Healey with Pat.
Unknown 3 - The Invisible Man drives to Harrow Lane with Pat Stevens in his Austin Healey.
Unknown 2 looks like it could be Emperor's Gate SW7
Unknown 3 could be just around the corner at the junction of Launceston Place/Cornwall Gardens SW7