Hollowcast lead horse and riders have been around for a long time. They have been dug at Jamestown, One is pictured in one of Humes books about colonial archaeology.....and they were still being produced well into the late 1800s....and even reproduced modernly. The best way to ascertain a safe date range for this one is by the context of your records of other finds in the vicinity. My guess by what I see remaining is late 1800s to the turn of the century. Cool little figure