NEW YORK — Billy Crystal, a comedic treasure now 74 years old, has aged into the role of Buddy Young Jr., a standup comedian who spent his glory years telling 1950s jokes on his own network show and playing Mister Kelly’s in Chicago, only to fall into the oblivion of playing all-purpose rooms in Florida retirement homes. When Crystal first took on the fictional character in the self-penned 1992 movie “Mr. Saturday Night,” he did so with the aid of prosthetics. At this juncture, he can draw from what he sees, and surely feels, when he looks in his own unforgiving mirror. That kind of courageous…
