My first post, way back at the start should have been
"This look like light scatter in Pinhole photography, was this a pinhole?"
I thought it, and should have added it to my questions of processing. When I was doing a lot of pinhole I saw them all the time. Even in when not pointed at a strong light source.
One thing maybe to prove this to you is that you can find the same pattern on different frames. Now one roll may not be enough to see, But on the hundreds of pinhole frames I have done I could see similar patters of black spots.