Storage unit back in prewar days (6)
I believe the answer is:
drawer
'storage' is the definition.
(thesaurus)
'back in prewar days' is the wordplay.
'back' shows that the letters should be reversed in order.
'in' indicates a hidden word.
'reward' can be found hidden inside 'prewar days'.
'reward' reversed gives 'DRAWER'.
'unit' is the link.
This may not be correct. It may be part of another bit of the clue.
Can you help me to learn more?
(Other definitions for drawer that I've seen before include "Artist" , "Box-like container that slides" , "One signing cheque" , "Part of cabinet" , "It slides into the furniture" .)