For sixpence, he treats hides (6)
I believe the answer is:
tanner
'for sixpence' is the definition.
(I have seen 'Old sixpence ' mean 'tanner' so perhaps 'sixpence' could also mean 'tanner')
'he treats hides' is the wordplay.
'he' becomes 'Tan'.
'treats hides' becomes 'ner' (I can't justify this - if you can you should give a lot more credence to this answer).
'tan'+'ner'='TANNER'
Can you help me to learn more?
(Other definitions for tanner that I've seen before include "Person making hides into leather" , "He cures hides, for an old sixpence" , "one getting bronzed?" , "Leather maker or old sixpence" , ".One who cures animal hides" .)