Some structures are now appearing on the layout. The engine shed will be part of a larger workshop of sorts, which will be low relief in front of the rear part of the loop.
The back of the engine shed will be curved to follow the curve of the loop to make it look like it isn't a roundy roundy. I hope that makes sense.
The fuel tank is a left over from my HO days. It will receive larger diameter pipe work than it has now.