Actually the sky is original, separated into a black and white layer. I started with a heavy dose of dehaze on the photo and worked on shadows, highlights, and contrast before making the black and white layer. Then I worked to maximize the dark and foreboding look of the sky layer. I did add some color to the sky in one later and weak version of this photo. When I rework the photo I will look into perspective correction, although I am not at all displeased with the positioning of the gravestones. They are not perfectly vertical in the cemetery and are about 130 plus years old.