I had that kit, but was pursuaded to trade it and I regretted for many years. I recently found an Orient Express on Ebay which is the same kit just different decals. They do pop up on Ebay but you have to be patient and be prepared to dig deep in your pockets for it. As others have said if you buy two of the reissue KW cabovers you can build your own for a fraction of the price of the Revell kit.
You could do that but you will have some problems to solve to do a similar build.
First...the cab is too short in the AMT K123 kit (if that matters), it has a 86 inch cab and the Revell kit has a 108 inch V.I.T. cab and yes you can of course lengthen it as you in this case will have two cabs.
Second...the rear suspension on the AMT kit is a Hendrickson Walking Beam and I don't know how you can do to modify that to a Tri-Drive as the beam that holds the two drive axles are hanged from the center, the Revell kit has a KW AG 100 air ride wich is easier to do a Tri-Drive with...the AG 100 suspension from the AMT K100 Aerodyne is available in resin from Melbourne Model Truck Accessories wich is complete with drive axles and prop shaft but you'll need two sets to do a Tri-Drive...of course everything can be done but I don't know if it's worth it.
Another way to go is to base the build on the AMT K100 Aerodyne kit, in that case you only need one more suspension kit and some wheels, and you are close to done...you don't even have to lengthen the frame as it's probably long enough as it is.
But Revell AG has reissued some of their truck kits recently, the Peterbilt 359 Tractor and the 359 Wrecker, the KW W900/T900 Tractor and W900 Wrecker, so hopefully they will reissue the K100 kits soon....I have suggested that at their "Share Your Dreams" site a couple of days ago so you can go in there to vote for it. http://ideas.revell....deas/item/4054/
Edited by Force, 20 May 2014 - 06:20 AM.