I'm still not exactly sure what the problem is but I have a feeling where this is going to wind up. So let me just jump ahead to where I think this is going and see if we can get you going again.
The problem with the rollingstock comes from my reusing the ver3a and 3b file name description. A few people have this confused these with the previous 3a and 3b versions released after Canton. Without going into the details how this happened you have to use the new ver3a and ver3b files. The reason is because the old versions contain only the Alco engines. The new ver3a and ver3b files contain all the Canton rollingstock plus all the upgrades and realistic physics that made up the previous updates. So before where you had 4 rollingstock files and a number of updates to install you now only have an install that goes like this:
Install Canton, Suddenly and then Thompson.
Install Canton Rollingstock Ver3a, Ver3b and Ver3c.
If you have the previous Canton or Suddenly CD you might still only have the old version 3a and 3b you are installing. You can tell the difference because the old files are pretty small at 5 megs. The new files are 24 and 25 megs each for ver3a and ver3b.
If you have the Thompson CD you have the new rollingstock files in the rollingstock folder so you won't have to download anything.
This will most likely clear up the confusion.
Now one more thing too. Dick created some extra canton equipment that you may be installing instead of the required stuff. Can't do that. You have to install the 3 rollingstock files mentioned above. The extra equipment Dick created is optional.
Hope this helps!
Rich Garber