Wasn’t much to be working on a weapon (1,6)
I believe the answer is:
a trifle
'wasn't much' is the definition.
Both the definition and answer are adverbs. Perhaps there's an association between them I don't understand?
'working on a weapon' is the wordplay.
I cannot quite understand how this works, but
'on' could be 'at' (I've seen this in other clues) and 'at' is found within the answer.
'weapon' could be 'rifle' (rifle is a kind of weapon) and 'rifle' is present in the answer.
This accounts for all the letters.
This may be the basis of the clue (or it may be nonsense).
'to be' acts as a link.
Can you help me to learn more?
(Other definitions for a trifle that I've seen before include "Slightly" , "somewhat" .)