In 1972 my friend Bill Larkins took this photo of the Douglas DC-7C used in the movie American Graffiti. The airplane was parked at Concord airport (California Bay Area) for the final scenes where Kurt boards the airplane to go off to college.
Here's what a DC-7C looked like when it was the "hot ship" of the commercial airlines. Pan American's "Clipper Flora Temple" gets waved-off at San Francisco on a beautiful day in 1959.
Before Lear Jets and the subsequent development of corporate aviation there were these: surplus WWII medium bombers that were converted for executive travel. This one's a Martin B-26 Marauder and has been heavily modified and has large three-blade DC-6 props in place of the stock four-blade units. My friend Bill Larkins shot this one at San Francisco in 1956. The Lear Jet didn't fly until 1963-64.