When I got the skis down from the garage attic to set them up for my
new/old boots, I took a look at one old pair with Look rotary heel and
"Sensor" toes. The toepieces were swinging around without constraint,
which I didn't remember them ever doing before. Then I noticed a big
metal spring lying on the floor, and THEN, I noticed that the toepiece
plastic shell had split in half (from the compression of the spring?),
and the missing parts were nowhere to be found.

Another thing I would rather not have known - when I took the bindings
off the skis, I saw that one of the screw holes had been originally
drilled about half a screw-width off, and a metal helicoil insert
installed to fix it.