Season 5 Episode 4: I Always Wanted a Swimming Pool
Thames Valley 681 (HBL 83), a Bristol LS6G/Eastern Coachworks, appears in the opening scene:
(thanks Ashley Hoare)
Season 5 Episode 10: Ward of Court
A glimpse of a London Country AEC RT:
Marker (Alfred Burke) crosses behind London Country MBS291 (VLW291G), a 1968 AEC Merlin/MCW operating from Windsor garage:
Season 6 Episode 12: Egg and Cress Sandwiches
A character played by Brian Blessed emerges from Stonebridge Park railway station to see a London Transport bus garage in the distance - Stonebridge Park?
Season 7 Episode 10: Lifer
It's not obvious from this view that this is a London Transport AEC RF ouside Marker's office:
.....but the reflection gives it away:
Season 7 Episode 11: Take No for an Answer
An AEC RF, but this is one of the twenty-five private hire RFs. As these had all been withdrawn from service with London Transport in the early 1960s, I guess this is RF10 (LUC210), which by 1975 was in preservation:
Season 7 Episode 12: Fit of Conscience
Another red AEC RF, again outside Marker's office: