(image borrowed from Disney Wiki)
Marc Darvis is the one who developed and refined Tinker Bell. Margaret Kelly was an actress who modeled for for him for the character inspiration. Though Marc wasn't the first to draw her, other artists such as Bianca Majolie started doing concept art in the 1940s.
(image borrowed from Villains Wiki)
According to Albert Lozano, a designer, "If you were to blend Errol Flynn, Clark Gable, Howard Hughes, and Walt Disney into one heroic 1930s man," you would get Charles Muntz. Though there is supposedly no connection with his name being similar to Charles Mintz, who was Walt's Universal distributor.