OK, as I said on page 1, I'd scan in once they had dried. Image 1 is the mask that I used. I also had a square piece of card held underneath for the long burn in, which was removed when I did part 2 (main exposure of the land/Obelisk and a small burn of the sea. Image 2 is obviously the bad burn in. I held the mask up to high in the picture and didn't move it.
Image 3 is not as bad, but I can see a slight halo around the left side of the Obelisk and darkening on the right.
Without any burning in, based on the base exposure of 26 secs, there was zero detail in the sky (I never actually did a base print, only test strips of the sky....I'm a tight wad, OK)