Heron...
I could not see the spots nor could I see any detail in the last until I went to a different monitor, I think I need another monitor...
You could check the rear bevel of your J12, some (mainly the Kiev mount) have an unpainted (black paint missing) ground glass bevel on the rear optic. If you got one of these you may need to have it painted - for high contrast shots, as otherwise you will get what look like strange light leaks! You seem to have some other flare/leak problems that would not be attributable to the J12, but I like the photos.
Noel