If you’ve ever worked in maintenance, active production, etc, you’ll be lucky to even have schematics. And trust me, there are a lot of hacks of people fucking with controls for 30+ years straight that soooo much of it is full of “fixes” like this, whether it’s something pushing a button in, or pieces of metal instead of fuses, or wires jumping over what’s “in the way” like whole safety systems and e-stops, contactors forced to run, etc etc etc.