The Fairbanks-Morse truck is from K-Line. It is 0 scale. It's packed away right now but I would guess it's about 6 inches long. I believe Yat Ming made most of K-Line's vehicles but that is just a guess based on similarities.
Originally Posted by Alan P:
Southwest Hiawatha, who makes that F-M truck, and how big is it? That's the Mack R from my wish list.
Just for reference, here's a Louisville and a Transtar COE: