Here is my 5-car set of TTX "cutdown" cars made from MTH husky stack cars. Around 2005, Gunderson/Greenbrier started cutting down 48ft well cars to 40ft for BNSF and TTX. They did thousands, and here is an example of the yellow DTTX variety, very common on stack trains today.
I already posted pics of this before, but I made three significant changes:
1) I repainted them so the TTX yellow color is much closer to the prototype. Previously, they were just too "sunny".
2) I converted them from 3-rail with lobster claws to 2-rail with 743 kadees.
3) I re-decaled them so they have much more accurate markings.
I would like to give thanks to Brett Nguyen for his many detailed up-close photos on RRPICTURES.NET
In general, I am converting all my 40-ft wells to 2-rail. So far, I have three sets of 5-car articluateds including 2 Maxi-I's and this 5-car shorty. In the future, I am going to convert my Maersk Maxi-I to 2-rail, as well as my APL LoPac 2000.