Bring back old American guitar (3)
I believe the answer is:
axe
'guitar' is the definition.
(informal term for a guitar)
'bring back old american' is the wordplay.
'bring back' is a reversal indicator.
'old' becomes 'ex' (prefix meaning former or onetime).
'american' becomes 'a' (common abbreviation - e.g. in organisation names).
'ex'+'a'='exa'
'exa' in reverse letter order is 'AXE'.
(Other definitions for axe that I've seen before include "Do away with" , "Fire weapon" , "flower in Devon" , "Tool for chopping wood" , "Tool for cutting, chopping" .)