I'm looking for 4 particular rack nuts for an older HP rack. These are the nuts that are trapezoid shaped, and have a spring on the back. Not a tension/flat spring, a coiled spiral spring. In addition, these racks use two different size nuts. One size hole (larger) for the L angle brackets, and a different size (smaller) for the rails that mount a 2100 cpu because the (different) bolts have to clear the inside of the rails. I am guessing these are not a common item that I could find at a hardware store. Would anyone have 4 to spare? Is there possibly a source for these still? Jay West