word of advice: The Cloning Brush is your best friend here. Use a hard clone brush, and swivel back and forth between the two. Also, make sure to clone from many different areas of the image, cuz even if you do use the clone tool, if you only use it near the seam itself, it'll still be really visible that the images were "glued" together if you don't. also... the three sheds... two of them are a lot "bluer" then the other (the ones on the right). Might wanna tweak them colours a little more...