Honestly doesn't look like anything that can't be replaced with normal hardware store goods.
I would make a new harness out of PVC in much the same shape. I'd drill into the front and back pieces that go over your shoulders and put a screw through the PVC and a military web belt and tighten it down against all four 'legs' with nuts. Next I would buy some pipe insulator or a pool noodle to loop between the two pipes that go upwards into the head. You can secure either with duct tape.
Also to make the rig more comfortable, you can heat the PVC pipes over your stove top to soften them, then bend them to a shape more of your liking.
Ambitious but rubbish.