Since I don't have the money for one, I decided to try my had at making one. I think it will work until I can buy one. This is the first time I have ever attempted something like this. I think my nest one, I will make from leather.
Wire Core, wrapped in cotton rope, wrapped with adhesive cloth and then wrapped in a waterproof tape.
You have the right idea for the shape, but I think it might be a tad too small all around.
You can kind of see how big it has to be to fit comfortably around the horse's nose - compared to the rest of the hanger and your hand, I am worried that it will be too small. I would suggest if you can go to a tack shop and get rough measurements, that will give you a reference point.
The other thing to watch for is equality, you want it to be very very symmetrical. If it's not, it can send the wrong signals to the horse, and worse, rub.
It's a great first attempt, no doubt about it.