In the scenes where Dian drives from the town to the mountains in a land rover, the vehicle used is Series III Land Rover, which first went into production in 1972, in 1966 the Series II was the production Land Rover, and sported a wire grill, and inset headlights, as opposed to the III's plastic grill, and lights in wings, as in the film.
After Dr. Leakey has instructed Dian Fossey about the jeep, a man in a beige suit beckons him to the plane. In the next shot with Leakey near to him, he is suddenly wearing sunglasses, but in subsequent shots after they've run to the plane and turn around one last time, the sunglasses are gone again.
Diane did not try to convince Leakey to send her to Africa, nor did she volunteer to remove her appendix, quite the opposite: In 1966, Leakey contacted Fossey and urged her to study gorillas in the wild as an experiment. At first Fossey was reluctant citing her lack of experience, but eventually agreed upon further coercion. To test her enthusiasm Leakey asked Fossey to have her appendix removed in the pretense of health measures which she then did.
Simba's newborn son is very dark with lush fur, and quite active. Newborn gorillas are usually pale with sparse hair, and are quite helpless and unable to move around much. The baby gorilla shown is at least a few months old.