Town is forward about modern centre (7)

I believe the answer is:

adelong

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

'forward about modern centre' is the wordplay.
'forward' becomes 'along' (I've seen this before).
'about' indicates putting letters inside.
'centre' indicates the central letters.
The middle letters of 'modern' are 'de'.
'along' placed around 'de' is 'ADELONG'.

'is' is the link.

Can you help me to learn more?

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

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