Typically, automotive interiors are "leather seating surfaces", which means that everything your butt and back doesn't touch is vinyl. May be some exceptions on higher-end cars (my Lincoln LS seats are ALL leather), but this is the norm.
The 1992 sales brochure lists leather seating surfaces under the Preferred Packages section. If you look closely at the seats, you will see that there is a difference in the grain/pattern and the shade of color between the seating surfaces and the other parts of the upholstery. This is more noticeable with light colors. Even the side bolsters and the headrests are a mix of leather and vinyl.