In 1998, this model was released in the Mare & Foal Series 2 - Appaloosa #3955. Set included a Black Leopard Sliding Stop QH and Bay Appaloosa Romping Foal. This set was considered a Special Run or Collector's Edition, and produced by Creata International for Specialty Market stores (smaller retail stores). This set has the same pattern, but different color, as the previous Mare & Foal set.
Side note: This may be an updated version of the Black Leopard Appaloosa Sliding Stop QH from set #3960 from 1996.