I started reading your Old Hollywood Scandal series with Garbo and working backwards. May I add a small story that speaks to Cary Grant's character?
My dad attended LA High School (1946 grad). One of his best high school buds was the son of the casting director on The Bachelor & the Bobby Soxer ... so my dad (as well as the group of friends) got to be extras on the film (shot at Beverly Hills HS). One day, during the filming of the basketball game scenes, the guys were standing around during lunch break when Grant approached them and asked them where the best burger could be had in the area. They told him, and then he said, "Well, come on then." Grant not only drove the group but treated them all to lunch.
Dad says Cary was one of the most down-to-earth, open and friendly guys he has ever met.