to get it just perfect you'd need to dicker around with the years but
Ernie Hudson as Rawlings- so perfect. I hadn't thought of him until you wrote that but perfect.
Denver Pyle - Ebeneezer.
Morgan Freeman- as uriel (I think this is a given)
Anthony Hopkins as The merlin
Harry- Harrison Ford crica 1985- the confidence smarts and look of 'oh no' when it doesn't work, most people know he gives good glower but spielburg remembers he's great when he grins.