Another American author's way of addressing James (6)

I believe the answer is:

ohenry

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'another american author's way' is the definition.
I don't know anything about this answer so I cannot tell whether this works.

'of addressing james' is the wordplay.
I cannot quite see how this works, but
'of' could be 'o' and 'o' is found within the answer.
'james' could be 'henry' (synonyms) and 'henry' is located in the answer.
No letters remain.
This may be the basis of the clue (or it may be nonsense).

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I've seen this clue in The Guardian.

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