The Box of Delights (TV series)
Patrick Troughton was a familiar face on BBC TV from playing the Second Doctor in "Doctor Who"; a contemporary "Blue Peter" feature on the drama makes the connection that in the role of Cole Hawlings, the kindly Punch and Judy Man, Troughton was playing another mysterious, scruffy time traveller. Renny Rye noted that Troughton "who was my favourite Doctor Who...had a quality that is unsurpassed, I think, as someone to pull you into a tale."
Doctor Who and the Daleks in the Seven Keys to Doomsday
Originally, the part of the Doctor was to be played by Jon Pertwee, but the role went instead to character actor Trevor Martin. Martin had previously appeared in "Doctor Who" as a Time Lord in the 1969 serial, "The War Games". In the play, it is stated that Martin's version of the Doctor is regenerated from Pertwee's; this makes him an alternate version of the Fourth Doctor. (The play premiered about two weeks before Tom Baker began his television tenure as the Fourth Doctor).