Brass instruments to buy after leaving university in Sydney suburb (7)

I believe the answer is:

hornsby

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'sydney suburb' is the definition.
I know nothing about this answer so I cannot judge whether it can be defined by this definition.

'brass instruments to buy after leaving university' is the wordplay.
'brass instruments' becomes 'horns' (I've seen this in another clue).
'after leaving' is a deletion indicator.
'university' becomes 'U' (abbreviation as in UMass).
'buy' with 'u' taken out is 'by'.
'horns'+'by'='HORNSBY'

'in' acts as a link.

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

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