sisu,
Back in the 30s Beechnut, the chewing gum folks, used a Pitcairn auto gyro for advertising. You might try their web site, or e-mail their public relations folks, to see if they have pictures. There were a lot of pictures at the time. Aviation was the hot topic in the 30s.
The Ford Museum in Dearborn Michigan has a Pitcairn auto gyro and they may have pictures. Amelia Earhart set an altitude record in a Pitcairn auto gyro, and had a minor crash in one. A search relative to her may pop the pictures of the auto gyro.
The Detroit Michigan newspaper operated a Pitcairn auto gryo. I think it was called the Detroit Press or Detroit Free Press, or Detroit News, something like that. They may have pictures. I think it is the same paper there today. E-mail their public relations folks.
Just some thoughts. rangerj