Who is Dufford Charleywood from When the Lion Feeds and what is their importance?

Meeting Sean during a bar fight in Dundee, Dufford offers Sean a partnership in business. Tall, and with a soothing English voice, Dufford has a gauntly ravaged face that greets you with sincerity. A gentleman, he neatly uses his cane to dispatch two of the men intending to fight Sean. Though employed at Dundee Collieries, Ltd. when they meet, Duff leaves his job to work with Sean. Having learned his mining skills in Canada, Duff is invaluable to Sean.