I spent a few years in the 80s as a VP at AMEK, a British console maker (the desks are still highly regarded) and I spent a lot of time at the factory in Manchester, UK. I remember distinctly all that went into building a world-class recording console.
That's what makes the following SSL factory tour video from Pro Tools Expert so interesting, at least to me. The conditions and methods of building a console have come so very far from those old analog-only days.
Here SSL's Jim Motley takes us through production of Duality, AWS and Matrix consoles from beginning to end. It's not totally in-depth, but still a good overview of the process.