Crossword Genius

Very old figure kept in step (5-3)

Ross

I believe the answer is:

stone-age

'very old' is the definition.
(I've seen this before)

'figure kept in step' is the wordplay.
'figure' becomes 'one' (I've seen this before).
'kept in' is an insertion indicator.
'step' becomes 'stage'.
'one' going within 'stage' is 'STONE-AGE'.

(Another definition for stone-age that I've seen is " Primitive".)

I've seen this clue in The Times.
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