Comforter, excellent for so-called gangster (8)

I believe the answer is:

scarface

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'so-called gangster' is the definition.
(I've seen this before)

'comforter excellent' is the wordplay.
'comforter' becomes 'scarf' (I can't explain this - if you can you should believe this answer much more).
'excellent' becomes 'ace' (I've seen this before).
'scarf'+'ace'='SCARFACE'

'for' is the link.

Can you help me to learn more?

(Other definitions for scarface that I've seen before include "Film starring Al Pacino" , "US gangster" , "Al Capone's nickname" , "Al Capone, or Tony Montana - 'Say hello to my little friend'." , "American gangster" .)

I've seen this clue in The Times.

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