The CK has a D1-6 spindle configuration. Came with, at first glance, a decent Cushman 3 Jaw Chuck. Still need to take a closer look at the chuck and maybe teardown and rebuild.
Naked 
Chuck off resting in cradle 
Cushman 3 Jaw
Needed a cheater bar, small 1″ black pipe, to slide over chuck key handles more for grip than for leverage. The cam locks were stiff but not stuck. Chuck came off with little fuss.