F3HP light leak?

Picked up a F3HP recently that seems to be in great shape and lightly used, as the electronics on my previous one crapped out, but I've been finding what I gather is a light leak in pictures taken in bright sun. Thoughts? Anyone had similar exp with an F3? Fixes? Just wanted to throw it out there to see if anyone had suggestions before I begin to try and trouble shoot it. I'm attaching an example picture. They're pretty consistent across the contact, but as far as I can tell only in very bright sun.

Usually it's the foam around the seals of the camera back. This tends to fail after a couple of decades. It's a reasonably easy repair.

Might also be the motor drive rewind cap is loose or missing, on the bottom of the camera. The above fogging shows its would be the bottom of the camera, and in bright light some photons could squeeze in there. Are you shooting with or without a motor MD4? If your missing the cover, Ebay has them or a bit of black plastic tape works in a pinch. I prefer the actual cap.

You can see about where the fogged area is by setting a strip of exposed negs across the film aperture. Maybe, sorta.
I also notice a shadow of sprocket holes towards the left that would suggest the film was on the take-up spool at the other end of the camera when it was fogged. Just below the "O" in Kodak.