Finding episodes at this point is extremely hard unless we find out there were a lot more film technicians that were Doctor Who fans. Which we've found 2 in the last decade so you never know.
Were they fans though? Francis Watson grabbed the two episodes when being told to dispose of films in the projection room, and took them home to screen at his local film club.
Terry Burnett just happened to mention to Ralph Montagu that he had episodes in his collection.
I don't recall either of them stating they were fans of the series. Then again I didn't hear them say they weren't!