(1972, Paul Naschy, Patricia Loran)

Unpleasant modern-day retelling of the Jack the Ripper Story.
An early street scene shows a London Transport AEC RT in traffic while a Green Line RC-class 1965 AEC Reliance/Willowbrook heads away from the camera. More of this later:

An RML-class AEC Routemaster from the NML_E batch crosses in front of a second RML, with a Red Arrow AEC Merlin in the distance:

A distant and early appearance by a DMS-class Daimler Fleetline/Park Royal:

Two standard Routemasters at traffic lights, RM553, followed by what might be RM2085:
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Here's where it gets a little strange. We see Green Line RC4 (CUV62C), a 1965 Willowbrook-bodied AEC Reliance, at Piccadilly Circus on route 711 to Reigate, then another RC passes in the other direction. As it sets off along Regent Street, it's clear this is the footage from the beginning of the movie, repeated: