When Pertwee was cast as the Doctor, the producers were figuring out how to play him that would be different from Patrick Troughton's interpretation. They said, "Why don't you play yourself?" Pertwee said later he responded, "Who's that, then?" He claimed he never really played himself - he always played a character. Kinda like Peter Sellers, who said more than once, "There USED to be a 'me,' but I had him surgically removed!" But Pertwee gave us one of the more unique Doctors, more like Bernard Quatermass, and it worked. But he actually played Worzel Gummidge even longer than he played the Doctor. A remarkable performer, and we still miss his style.
Just a minor point, the clips from ITN News at Ten with Trevor McDonald are ITV and not BBC. It feels like yesterday hard to believe this was 27 years ago. If he had lived another 10 or more years he'd have seen the show return. I do remember he was interviewed when it was announced the Paul McGann version was being made but sadly died before it was broadcast.