Hey ColdWar ;o)

i've done this :

• 3 layers : foreground, the machine, the sky.
  --> contrast, level and curves + manual touch to the foreground
  --> excessive contrast on machine to just have black and white
  --> curves on the sky

I've associated layer by layers to erase what i want to have on the final image.

After that some manual finitions ... ho yes, and 2 unsharp mask with different selection.
About 15min ..

Seeya ;o)
Olivier