"I see Bob Hoover's name on the canopy, but wasn't this one of Leroy Penhall's planes? I think that is Hoover's Mustang behind it and another Penhall plane (a T-33) behind the Mustang. At one point I think Hoover borrowed/leased Penhall's P-51 after his was damaged by the oxygen tank explosion, so maybe that is the Mustang in this photo? I believe Steve Hinton was ferrying it for Hoover and lost power after leaving Oshkosh and landed on a small road?"
This reverse angle photo answers some of your questions. The T-33 has 'Fighter Imports, Chino CA" on the nose. The P-51 does say "Penhall Co" on the canopy frame and has a white race #81 on the bottom of the left wing. This slide is really bad with dark dust. I started cleaning it but gave up. Too many other slides to do to spend that much time on this one, but I will post it as is.

I Found another trove of slides, and a reel of Cape May New Jersey 8mm film dad shot. I plan in digitizing all of that as well as time and money permits. Dad was a serious hobby photog I would say. He knew what he was doing but did not have top end equipment, and did it solely for personal interest. As I am finding it I am trying to preserve it and share with others so his work can be appreciated.
Thanks for the kind words from all and the interest.