Hey Apex;
One of the hats I wear is farrier. The rasps we use in the horse shoeing biz are really good. Check with your local farrier and ask him where he gets his rasps. I prefer "Save Edge" brand. They seem to last the best and are VERY sharp. I bet you will like them. There are also differnt kinds, like long ones for draft horses, really fine ones for finish work. They have two sides , fine on one side and coarse on the other and, the edges have teeth too.
I hope this helps.
Tom