Interesting. I don't think you mentioned the actual time it took from beginning to end to create the scene?
P.S: Using the objects as reference or for drawing over was a nice idea. That's about the only way I can draw things in photoshop. I'm not so good when it comes to trying to do something straight from my imagination, but I lack the patience to work so long on a piece of artwork, which is why I would always prefer to deal with other sides of game development such as programming, development, structure, brainstorming & troubleshooting, etc, as opposed to spending hours, days or weeks on a single background image.