An old rocker and a similar rocker placed in an earlier time (9)

I believe the answer is:

antedated

'placed in an earlier time' is the definition.
(to antedate is to come precede in time)

'an old rocker and a similar rocker' is the wordplay.
'old rocker' becomes 'ted' (member of the Teddy boy subculture).
'and' is a charade indicator (letters next to each other).
'similar rocker' becomes 'ted' (member of the Teddy boy subculture. I am not sure about the 'similar' bit.).
'an'+'ted'+'a'+'ted'='ANTEDATED'

I've seen this clue in The Guardian.

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