Regular Run Stablemate Assortment
Though the real Seabiscuit was without any white, #5024 could be found with a wide variety of leg markings. This particular model sports four socks, some of which could probably be called stockings. He's also on the lighter end of the Seabiscuit spectrum; some models can be quite a dark bay.
With being discontinued at the end of 1990, #5024 just missed the new plastic change-over. His replacement, #5025 "Running Thoroughbred" in black, would make that leap instead.
As you might have guessed from the name, this mold was sculpted as a portrait of the real Seabiscuit. The picture in the sidebar of his Wikipedia article looks a lot like the Stablemate mold, don't you think?