These well cars are from Jacob McKee's, Getting Started with
LEGO Trains, with minor modifications. See the following for
more info: http://www.bricksonthebrain.com/trains/index.cfm

Perhaps my biggest innovation is the poor-man's containers
that don't use the expensive doors or plates (go up one or
two levels if you are curious). Which also allows for wider
color variation.

As for the building experience, finding the yellow brackets
in quantity was the hardest part. In retrospect I'd recommend
using black ones (they match the design and you can't see 
them anyway). For the moment I've bypassed using the yellow 
door rails while I'm still shopping for them. Instead I've 
used plates. Oh, I'd also recommend compiling your own parts
list before shopping, it's a lot easier that way.

--------
Benn
zephyr1934@yahoo.com