Place for valuables close, turning key fast (5,4)

I believe the answer is:

night safe

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'place for valuables' is the definition.
I don't know anything about this answer so I cannot judge whether it can be defined by this definition.

'close turning key fast' is the wordplay.
'close' becomes 'nigh' (similar in meaning).
'turning' shows that the letters should be reversed in order.
'key' becomes 'e' (musical key).
'e'+'fast'='efast'
'efast' in reverse letter order is 'tsafe'.
'nigh'+'tsafe'='NIGHT SAFE'

Can you help me to learn more?

(Another definition for night safe that I've seen is " In which to deposit".)

I've seen this clue in The Times.

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