... perhaps it was simply a chip that was handy that was improvised to make a spacer or a washer or some other replacement device.

Here's an example I had to do just this summer. My pool liner was pulled out of the extrusion track under two of the concrete coping corner when I opened the pool this summer. This isn't the first time this has happened and with the pool filled with water, the only way to get the top of the liner to snap back into the track is to drain most of the water out to relieve the weight in order to lift the liner up.

Well after I had pushed the liner bead back into the extrusion track, I cut strips off of a few slot cards I had handy and wedged them in between the bead and the extrusion track. So far, no problems. Will find out for sure next summer.