On the chart posted by VP Navy, shoe number 8 is a mule shoe, and I have nailed on lots of those shoes when I was younger and dumber. 5, 6, and 7 are corrective shoes, and if the horse needs that style of shoe, a good farrier will make one today. I've built shoes just like number 1 for the back feet of a show horse that the owner wanted to have the horse slide to a stop. Almost impossible to date a horse shoe unless it's found with something that you can date. Your find was left on the horse way to long, and the shoe wore in two at the toe. Either that, or they were in very rocky ground that caused it to wear faster than normal. Your shoe has also been cut off square at the heel, which isn't the normal way it's usually done, so I would suspect it was either for a back foot on a small horse or pony, or possibly a small donkey or a smaller size mule.