i myself do farrier work, so i made my own set. Since then i have made a few different pairs for a couple guys. Tandy sells a chap pattern pack, i just modifed the chink pattern ( added some length). what i can suggest is that on the front and wrapping in towards the inner thigh sew a heavier weight leather (6/7oz.) on top of the chap leather. Reasoning behind this is because of the horse leg being held there and when rasping, ofthen the rasp rubs agenst the chaps, causing faster wear. Sewing a piece on top of the chaps will allow wear on that leather and then to be repalced if needed. I will try and put some pictues up tomorrow of my pair. The other suggestion is on the knife pocket, put a snap on the bottom of it. while rasping, filings often fall into that pocket, the snap on the bottom makes it easier to clean out, rather than turning them upside down.
Duke