There are collectors for such old toys. The value depends on the condition, unfortunatly it seems one ear of the horse is missing. Still, depending on how many are still around, it may sell for $50 or even more, if a collector really wants this to complete his collection.
Is the walking mechanism electric or mechanical to wind up like a clock? If its mechanical, try to find a matching key and try it out. If it still works its a plus for a sale.