Collectors think of this, though, and have specific variations listed on the affected releases. Together, they can be described as the "@BW" group. The what? Well, perhaps it's better to illustrate than describe. My example is the 20130 Burlington Route box car, since both versions happen to be part of the UMTRR Accumation. There are several other Micro-Trains releases to which this also applies, but I think this will convey the idea. Here goes...
The 20130 car had one side printed with the slogan "Way of the Zephyrs" and the other with "Everywhere West". One of the two sides is designated as being the "brake wheel side" because the section of the side to the right of the door is adjacent to the end of the car which has the brake wheel. (If only North American freight cars normally had two brake wheels... never mind.)
On the prototype, of which there was only one in this case, by the way, there was only one way in which the car was painted. Either the "Way of the Zephyrs," or "WOZ," slogan, was on the brake wheel end, or the "Everywhere West," or "EW," slogan was. It couldn't have been both.
However! Kadee, when producing these cars, didn't run them all through the painting process in exactly the same way. Therefore, some proportion of the cars, no one knows how many, were produced with the "Way of the Zephyrs" slogan on the brake wheel side, as seen in the scanned car to the left here. This is called the "WOZ@BW" variation.
And the remaining proportion, again, nobody knows how many, were produced with the "Everywhere
West" slogan on the brake wheel side, as illustrated by the scan here. This is called the
"EW@BW" variation. By the way, in terms of aftermarket collector value, the two versions
are about the same. That's not necessarily true for other catalog numbers which are examples
of the "@BW" group.
In fact, the most spectacularly collectible variation in this class occurs on the 20072
Santa Fe box car, one of the "Class of '72" of original Micro-Trains releases. What I have
here to the left is the stock version with the "Grand Canyon Line" slogan on the brake
wheel side; that would be "GCL@BW." For a long time, it was considered to be the only
version out there. (If you ignore the size of the "Grand Canyon Line" slogan, but that's
another Micro-Story.) It wasn't until much later that it was realized and confirmed that
a version exists with the Santa Fe map on the brake wheel side, that's "Map@BW," and it's
quite rare. Rare enough to sell for more than $3,000 at auction! Is it a unique instance?
Well, probably not, but there may be fewer than ten out there. And there may be only one
in "collectible" condition. One UMTRR reader who will remain anonymous says he owns
five of the "Map@BW" variation... all weathered!