Having both the engine shutoff and brake booster not working suggests poor vacuum from the pump or a massive leak (which could be in the booster). If your door locks also don't work, that is a trifecta pointing to "low vacuum source". Try blocking off vacuum consumers until you find the bad branch and go from there.

Yes, if you mix up the 2 brown tubes, the engine shut-off won't work. The vacuum switch at the key is basically a SPDT switch. The "pole" must go to the shutoff valve, one "terminal" is the vac source and the other "terminal" is a hidden vent to the air.

That is an excellent assignment. I’ll have to wait till I get back home for that, in a few days.

I did check about six months ago and best I can tell the vacuum pump is working properly. Also the brake booster itself seemed to be sound. But I need to look at everything again. I have a guide from Kent about troubleshooting vacuum, I’ll refer to that, and come back here with questions.