I'd lay odds the owner did this job by searching through a box of old fittings and picking up anything that had vaguely the right ends to get to the next joint. There's even a multi-point manifold in there. That yellow hose looks like garden hose pipe. There's even an automatic air-bleed pot!
Why do rational intelligent people create these death traps in their own homes. I can't see even the local handyman expecting to get paid for this mess, so it has to be a DYI job.
