I don't think you can get some of the buildings you mentioned in a mystery box. I was under the impression you could only win the Tire Fire and Lard Lads out of it.
As far as Frinks Lab/Tire Fire/Volcano Lair/Springfield Sign/Duff Brewery out of the Buddha, it's possible. I've won Frink's lab from a buddha as well as Moleman, and 60 donuts instead of getting Moleman again.
The chances for Frink is decent. I've seen the odds listed at 1%, but I've watched some, um, 'tests' yield better odds for getting him and lab/150 donuts. Out of many tests, I haven't seen, nor heard of anybody getting the SF sign, Brewery, Lair or Tire Fire from it.
