Class: old, old actor (6)
I believe the answer is:
brando
'actor' is the definition.
(I've seen this before)
'class old old' is the wordplay.
'class' becomes 'brand'.
'old old' becomes 'o' (common abbreviation eg in OE for Old English. I am not sure about the 'old' bit.).
'brand'+'o'='BRANDO'
Can you help me to learn more?
(Other definitions for brando that I've seen before include "Oscar-winning actor" , "Actor who died this year" , "Marlon --, film actor" , "FILMSTAR" , "heart-throb" .)