"Captain Caruso" is a blue-and-yellow macaw, Ara ararauna.
Steed tells Samantha they will talk about "cabbages and kings ...". This is a quote from 'The Walrus and the Carpenter' by Lewis Carroll (from "Through the Looking-Glass and What Alice Found There").
The wall signs outside the photographer studio (one for 'Stone Street' and another mentioning a gallery) are also seen along the alleyways in "Escape in Time."
John Wood (Twitter) appeared in the 1998 film of The Avengers playing Trubshaw.
The triangle that is supposed to play a "Top C" for the parrot is actually playing a C-sharp.