I suppose the manufacturers could rely on the age old,"but it was only used by one railroad" excuse.....wait a minute, the 4-8-8-4 was only used by "one" railroad, and it is one of the most modeled locomotives! There isn't a whole lot of physical difference between the bigboy, and the Yellowstone.....just that the Yellowstone is better looking, and has a considerably larger boiler. Like the Allegheny, the Yellowstone is best described as a "brute!" The Caspar Lumber co. had two dimunitive standard gauge 2-6-6-2s, the Trojan and the Sampson. Little River Lumber had a 2-4-4-2 which they returned to Baldwin in exchange for a smaller 2-4-4-2. The first, ended up on the Deep River Lumber company.