It’s interesting to recall that Keaton initially got started thanks to "Fatty" Arbuckle, who noticed his talent while he was working as an extra on some "Keystone Cops" shorts. This documentary isn't really a look back at his whole career; instead, it focuses on him during the making of the Canadian film "The Railrodder" (1965). It’s clear that he was trying to recapture some of the success he had in the 1920s with f…