Come along if you want to see how I built it.
I started with a Masonite base painted black and a frame of scale lumber. All lumber, throughout the build, was cut to length and stained in a bath of India ink before assembly. For size comparison, an O scale figure is seated beside.
Next I cut wall boards from .4 mm plywood and glued in place.
I also added some doors, broken and hanging askew.
Next was the roof frame, and the upper part of the gables.
Now for an extra fun part. Fun because I had never done anything like it before: Metal corrugated roof panels, etched in ferric chloride to get a worn and rusty look. The warning in the how-to-pamphlet that came with the roof panels was true - it is easy to etch the panels to oblivion.
As seen I also added door hinges, made from styrene. The green is supposed to be mildew or fungus of some kind, but I not too happy with the result. I later tried to tone it down.
If you look carefully you can also remnants of batten on the side wall. I added a few of those to indicate that the shed originally had a board-and-batten siding.
Last, some more pictures of the shed in its final scene on the layout.