I would like to model a machine that looks like this. This kind of machine is called Petter Junior, it is a stationary oil engine.
The machine would be in an old form but with bright and reflective textures. The body of the machine would be colored by green, and the wheels would be in grey and black. The pipelines would be in silver and the parts would be in gold and bronze.
I also find a book that introduces the machine. Covering instructions for fixing, starting and working the engines, lubrication, magneto, fuel, fuel pump and has parts diagrams and layout drawings.
Details of the machine and how different parts of the machine works:
Ideally, the machine would be like an old machine that has been repainted and refurbished, here are some references: