If I can just jump in here, hopefully to give some new perspective, the title change has made things even worse - how are these actors 'guest appearing' in Doctor Who - was there a special credit for them in the titles?  Taking one random example - Tony Caunter in 1965 - how was he making a guest starring appearance when he was an unknown jobbing actor (and probably still is!). I can understand a similar article for The Simpsons being notable with the likes of Paul McCartney and Liz Taylor appearing, but the fact that you have to tell people why they are famous says it all really (if appearing in Crackerjack 30-odd years ago does actually make you famous!).