Old fellows on the mark going wild (3,6)

I believe the answer is:

off target

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'going wild' is the definition.
I don't know anything about this answer so I cannot tell whether it can be defined by this definition.

'old fellows on the mark' is the wordplay.
'old' becomes 'o' (common abbreviation eg in OE for Old English).
'fellows' becomes 'ff'.
'on' says to put letters next to each other.
'the mark' becomes 'target' (synonyms).
'o'+'ff'+'target'='OFF TARGET'

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I've seen this clue in the Sydney Morning Herald.

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