from The Century Dictionary and Cyclopedia
- n. One who alters the brand on cattle and steals them; a cattle thief who ‘duffs’ the cattle by altering the brand.
Sorry, no etymologies found.
Anyhow, no cattle-duffer in the colonies could have had a better pair of mates than old Sally and
What he had been once no man knew, though evidently he was a man of some little culture and education; what he was now was patent to every man -- escaped convict, bushranger, cattle-duffer -- even a murder now and again, it was whispered, came not amiss to Gentleman Jim.
They had been followed, and subsequently a man had been killed in the Grampians who had been identified as John Bradby, a noted sheep and cattle-duffer.
Anyhow, no cattle-duffer in the colonies could have had a better pair of mates than old Sally and Crib, if the devil himself had broken 'em in special for the trade.