Using photoshopped, colorized images of the side, entrance and roof of the real engine house, I have created a HO scale mock up of 2 sides of the engine house and one side of the roof. Images were printed on matte paper on an inkjet printer and glued to foam core board. The engine house was actually 150 feet long by 50 feet wide – this is a true HO scale mock up, so its a little over 20 inches long and 7 inches wide. I will likely improve the look of the mock up in the future with a thinner roof made with cardboard or plastic instead of foam core and some detail parts and add the cupola that belongs on the roof. I have found that Grandt Line makes 6 over 6 windows that should made a nice upgrade over the printed windows. Any edges of the foam core that show will be painted over.
A front view gives a little better perspective of how the mock up looks next to a Mantua General.
Finally a view of this section of the layout with the rough track plan highlighted in yellow with photoshop. This gives an idea of the proportions of this part of the layout. The water tanks would be just to the side of the engine.
The open space towards the bottom of the image will contain a bit of the bluff that was on both sides of the cut that lead to the wharf. The next module to the right side will contain a piece the end of the trench line that protected City Point, as well as some crossovers on the incoming tracks.