Very few major-league Hollywood stars have suffered such an abrupt and precipitous hair decline as James Stewart, and it all happened during his service as a bombardier squadron leader during World War II.
Before the war the rail-thin, tousle-haired Stewart looked fairly boyish; when he returned in ’45 he had developed widows’ peaks and stress fissures, and soon after (probably during filming of It’s A Wonderful Life or certainly before Call Northside 777) began to wear toupees. By the mid ’50s his hair was mostly gray and barely hanging in there.
Without the rug the older Stewart looked like an aging middle-management businessman or an Air Force General (which he was); with the rug he definitely looked younger but also like an actor wearing a rug.
Why didn’t Stewart take care of things “in Prague” via micro scalp implants? Because the technology didn’t really come into being until the ’90s or the early 21st Century.