Available as a single model #5019 Standing Thoroughbred from 1990-1994, and available in the Stablemate Assortment Set #5600 from 1991-1994. Released later in 1990, so not pictured in the catalog. These models were made from the heavier Cellulose Acetate plastic, except from 1992-1994 when they were made with the ABS plastic.
Side note: The yellow hang card pictured has a 1990 Copyright date, but the model inside was made with the ABS plastic (1st model pictured).