CHESTER, Mont. – Dan and Holly Frederickson don’t do things by halves. When one of their grandchildren developed a cat allergy that prevented him from staying in his cat-loving grandparents’ house, they bought a caboose, had it delivered from Bozeman, ripped it down to its studs, then meticulously restored it to above and beyond its former glory: a burnished barrel-shaped ceiling, a scraped and stained conductor’s desk, as well as cozy beds, a stainless steel kitchenette and a tiny, tastefully-tiled bathroom, all of it lashed to the ground to stay put in the gale-force winds that rip across Montana’s Hi-Line.