All tests are not equal: I’m still wrestling with the various definitions and categories of tests and how to best present the subject to you. The biggest problem is overlap; some models can fall into more than one of my categories, and I’m not entirely comfortable with that, for a variety of reasons I won’t go into today.
Nothing illustrates this problem better than the Palomino PAM that I discussed earlier. A few other hobbyists have informed me of the existence of other Palomino PAMs; I don’t doubt their authenticity. That's why I alluded to the possibility of others existing, before: the whole problem with Marney and the models that passed through her hands is that we still can't - and may never fully be able to - know what she had, what she did, or even begin to classify them properly.
First of all, I think we should add some nuance to our definitions, and distinguish the difference between a test color and a test run. A test color is a model with a unique (or nearly unique) paint job. A test run, on the other hand, consists of a small group of identically painted models: the quantity is usually in the single digits (5 to 7 are the most common quantities I hear about.) There may be some small variation in the run - color a little lighter or darker, or markings might vary a bit - but they are basically the same.
Marney distributed a lot of these small test runs in the 1970s and early 1980s. They were either sold directly to other hobbyists, or distributed as prizes at live shows, given away as gifts, etc. Nancy Young described a few of the more famous of these test runs in her book Breyer Molds & Models, including the Traditional Dapple Gray Man o’ War and the Shaded Dapple Gray Cantering Welsh Pony. (The Black Adios she mentions is another thing, and another topic altogether!) I have documentation for at least a couple more, including this heartbreaker from Marney’s album:
(The Appaloosa Performance Horse Proud Arabian Stallion - five pieces reputedly exist.)
Marney didn’t merely have access to the factory in Chicago, and whatever goodies it contained, she also had access to the painting booths and the painting equipment. While some of the models she acquired, either for her own collection or to sell, were actually test colors or test runs - done on behest of the management to test paint jobs, painting techniques, or to generate orders in advance of production - others were not.
Are these particular models actual test runs, or mini-special runs that Marney concocted herself? Honestly, it’s hard to tell. Marney passed away in 1992, and other than her photo album and a few letters, the only information I have comes from the memories of other hobbyists - and memory is not always reliable, especially after so many years have passed.
It’s possible that the Palomino PAM may have been a small test run, rather than a unique test color. These various Palomino PAMs could also simply be random models Marney made up over the years. Or a mini SR she made for whatever reason. It’s really hard to say at this point, until more evidence surfaces.
(Needless to say, if you have any paper documentation you'd be willing to share, let me know!)