Here are the people that played the roles of the cats in The Cats section of the site:
Rum Tum Tugger
Griddlebone/Jellylorum - probably not the same woman as the Griddlebone from the Cats section, but in the London 1981 cats musical she played as her.
Growltiger - probably not the same guy as the Growltiger in the Cats section, but he did play that character in the London 1981 cats musical.
pictures from http://cats.jachymov.cz/en/encastlist.html and Mr. Misoffelees picture from http://www.jacobbrent.com/ and Growltiger's picture from www.survivorstvseries.com/Stephen.htm