Jay that does look familiar and I will give you my thoughts on it then someone else can give you another side of it. That is a toe weighted shoe with a toe clip. Most likely hand made but you can buy shoes like it including ones cut out and you add the nail holes. The hard pad is a wedge to raise the heel of the hoof up off the ground. Like a bit of a higher heel on a boot. The leather pad seems to make it a bit more comfortable for the horse as there is just a bit of give to it. Even when nailed up tight. If you look at a shoe the round part in the front is the toe and faces the front of the hoof. The heels are at the ends of the two branches that extend back from the toe, and on this shoe they are thinned down. The reduces the weight on them and leaving more metal on the toe makes the hoof travel differently than if barefoot. Some horses tend to have heels that are low in relationship to the toe. Think about putting your bare foot on a board and let the heels come down to the floor. Then put the board under your heel and let your toes touch the floor. Some horses may need a bit of a lift in the heel. That is what the wedge pad is for. Like a heel on a boot takes a bit of strain off the interior stuructures in your lower leg. With the heels slimmed down there is a loss of flotation. Think how this shoe would sink into soft ground,,,heel first. The toe would stay up more on top of the ground. However the wedge pad, or any pad helps keep the heels from sinking..On hard surfaces the heels and toe would stay on top. This whole assembly weighs more than just a plain shoe, the toe clip fits into a little recess put in the front of the hoof wall and keeps the shoe from moving around which might make the nails loosen. They are a nice forgeing exercise and to forge a pair and add the pads, clip and nail the whole package is a sign of forging and fitting skill. In fact it is one of the farriers skills unlike artistic smithing, it wears out and has to be replaced on a regular basis.