I've only ever replaced them with originals. Often the slot that the anchor pin is inserted in breaks. What you can do is simply drill another hole in the spring and re-use it. I've done this myself, but it is not as simple as it may sound. The spring is hardened steel, and drilling through it can be difficult. And positioning and securing the spring in a drill press can be difficult as well. But it does work if you do it right.
