Garment for military vehicle commander? (7)

I believe the answer is:

tanktop

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

'military vehicle commander?' is the wordplay.
'military vehicle' becomes 'tank' (armoured vehicle).
'commander?' becomes 'top' (I can't justify this - if you can you should give a lot more credence to this answer).
'tank'+'top'='TANKTOP'

'for' is the link.

Can you help me to learn more?

(Other definitions for tanktop that I've seen before include "Warm garment" , "turret?" .)

I've seen this clue in The Daily Express.

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