Pictured above is a November 22, 1964 photo of William Sponsler (click on the image to see it at full size), a designer of the Lunar Surface Vehicle at Northrop Space Laboratories. In the photo he's checking the mechanism of a one-sixth scale model as it moves over a rubbled replica of moon surface. Over five years later on July 31, 1971 the first lunar rover would make it debut during the Apollo 15 mission.
Found via the UCLA Library.