Bryan Forbes is to be commended for assembling a glittering cast in this rather plodding adaptation of Robert Louis Stevenson's novel. It centres around the fate of a £20,000 fortune - the result of a tontine between 20 families who each invested £1,000 in a lottery than would provide the entire fund for whichever of their young children survived! Over the course of time, nature takes it's course until, sixty years later, we are left with two brothers. "Masterman" (John Mills) and "Joseph" (Sir Ralph Richardson). The former is a conspiring old fellow who really cares about the cash - a…