One "problem" is that Stan used the chassis as a testbed for different configurations, The photo from the WTVN demonstration, the backyard buggy demo video, and the video clip in the GNP bookplate are all of different configurations, over a period of years. So even though one might see two generators or alternators in one photo, it doe not mean that they are still part of the configuration several years later. I'll ask GNP if they have other views of the buggy version you are asking about and if they will release it for posting.
regards