Actor Paul (unlike actor Gary!) a reformed character (6)
I believe the answer is:
newman
'actor paul' is the definition.
The definition suggests a singular noun which matches the answer.
'unlike actor gary a reformed character' is the wordplay.
I cannot quite understand how this works, but
'a' could be 'an' and 'an' is found within the answer.
'character' could be 'w' and 'w' is found in the answer.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for newman that I've seen before include "Paul -, US actor" , "Cardinal - PC husband" , "Cardinal -- Paul, actor" , "John Henry --, beatified English theologian" , "Paul . . . . . ., deceased US film star" .)