Long story short, I installed a 3-leaf AAL and ditched the overload spring. For whatever reason, I tossed the overload springs and come to find out the I could actually re-use them (even though the instructions specified otherwise.)
I'd love to find a set of overloads, but it's looking as though it's not going to happen. My next option is to have a local custom-spring manufacturer make me a set. Before I can have this done, I need to get some dimensions of the stock overload. If someone could snag dimensions for the length, width, and somehow measure the curvature of their spring, I'd greatly appreciate it!