Well I did it today! My new tow vehicle is a 1994 Kenworth K-100 cabover with a 430 HP Detroit 60 series engine, 18 speed Road Ranger, 40,000# rear ends and a 90" sleeper. I paid $11,500 US for it and it is in great shape. The guy has owned it since new and ran it from Calgary to Houston most of the time. He kept impecable records and did regular "blood tests" on the oil. I will post some pics in the next day or two.
Now it's off with the fifth wheel, extend the deck and mount a hitch. Then the test drive.