The IPC is a good start - but try this: go to the front where it has "by part number" and look for MS21919, that will take you to the chapters and figures which only have them, should narrow it down a bit. Fuel definitely, hydraulics (landing gear, flight controls) definitely, wiring supports - maybe.
This should work well, unless it is a g0%%@mn BACR part number; then of course, find out what the BACR for a cushion clamp is and then proceed accordingly.
If you are lucky, the front of the IPC might even have quantity used, which should cut down your research time immensely.