The parts of the logbook shown in the listing seem to imply that this engine was removed in the 1980s when the plane was still registered as G-BFKW.

As for the plane, engines 3 and 4 are visible in a 2010 photo.¹ By 2015 the ducts had all been covered.², albeit № 3 haphazardly in the rear.³

¹ https://commons.wikimedia.org/wiki/File:Concorde_(British_AW...

² https://commons.wikimedia.org/wiki/File:Concorde_2015-06_673...

³ https://commons.wikimedia.org/wiki/File:Concorde_2015-06_692...