More like this!
The Wouda pumping station, 1920.
Now forgive my tech-OT, presuming Railcraft will be used for steam production, it's boilers are fire-tube tipe ones (deduction based on their explosiveness), they are used to produe high volumes of steam at relatively low pressure and temperature, their use in the energy industry has ended almost 100 years ago, so I would stay around 1890-1900s buildings as examples, @Epidemia87 's favoutire style (Even though steam engines vould be more realistic)
I tend to be a perfectionist when it comes to that kind of buildings
Well I am working with the tools I am given, theres nothing in the game that looks quite like those machines (yet!) I dont need it to be 100 percent historically/scientifically accurate. Id say my factory design has the same atmosphere as the pictures you posted.