They're at the tail end of this train. They're the 57-foot mechanical reefers (no sound) with scale wheels and shock-control couplers. Kadee came out with a shock-control draft box a couple of years back for use with Kadee 800/700 series couplers. They're still showing up on eBay from time to time mostly in 3-rail. These particular cars run on 36" wheels. Lionel has re-issued the cars in the LionScale line, but they haven't done the Santa Fe's yet. When/if they do I'll definitely get a set and convert them.
This is how they started out:
