http://www.tfu.info/1986/My1stTF/Truck/truck.htm cause I remember playing with that when my parents would drop me off at the sitters house...and I doubt she got rid of it even after 10 years...so if its worth something I might try to buy it off her
Board member Tfgraveyard just hooked me up with a set of all three for $20 + shipping, so I'd have to say no, they're not terribly rare. They do go nicely with my Playskool Gobots, though!