Darren Grimley, a science-fiction fan, has SF models which would not have been able at the time the series was set (the 1970s). In particular, a model of Deep Space Nine can be seen in one episode; this was not available until the 1990s.
In the second episode of the third series, Blondie's "Atomic" accompanies a scene. This episode is set in summer 1978, but the song was only written in 1979.