A few nice subcontract machining images I found:
Boeing 737-300-400-500 structure from beneath, electrical transformers.
Image by wbaiv
Here’s a page from the Alaska Airlines service manual. Its a standard drawing and text Boeing supply to the owners of their airplanes so the owners can construct the manuals that they are responsible for. Don’t they just buy the Haynes manual or the Bentley one when they are picking up parts? Nope. FAA regulations make the airline responsible for the complete and correct manual for the level of maintenance they provide. Lots of airlines subcontract the heavy checks, "C" and "D", and so people like Lufthansa Technik have the really deep stuff, but every airline does some of its own maintenance. The marked similarity between the drawing style here and in, for example, Bentley car manuals, comes in part from both being distributed via microfiche, as well as paper and computer. Hence the dry style with constant line widths and very few photographs.