Seasoned actor provides well established benefit (3,3)

I believe the answer is:

old pro

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'well established benefit' is the definition.
I know nothing about this answer so I cannot tell whether this works.

'seasoned actor' is the wordplay.
'seasoned' becomes 'old' (I've seen this in another clue).
'actor' becomes 'pro' (I can't justify this - if you can you should believe this answer much more).
'old'+'pro'='OLD PRO'

'provides' is the link.

Can you help me to learn more?

I've seen this clue in The Guardian.

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