I just recently found copies of the two old Doctor Who movies done back in the 1960's starring Peter Cushing as Doctor Who, and while watching the second movie Daleks' Invasion Earth 2150, I noticed that a young Bernard Cribbins was in that as well. He plays a character named Tom Campbell who was traveling with the Doctor.
Now I know that it doesn't really seem to fall in with any of the Doctor Who canon exactly, but despite that fact, it seems Bernard Cribbins is a Doctor Who veteran. Appearing in both the 1960's film and then again as Wilf in the new Doctor Who TV series.