This model was originally sculpted by Kitty Cantrell. You can see more of her work at her website: http://www.kittycantrell.com/stonehorse.htm.
The Chips Rearing Horse mold was finished in 2008, and as you can see, on many of the models today, that original date is still marked underneath the back legs. Regular releases of this mold did not start until 2012. I do not know what the official first edition model is.