My wife has worked as a quality engineer in a polymer lab, and reports
that one of the difficulties with modern materials that fail too soon
is "recycling".  Plastics (and that can include natural stuff like
rubber) generally work because they have long molecules.

It's been said, not necessarily in jest, that an automobile tire is one
huge rubber molecule, and that's why it is strong.  If the long-chain
molecules in a plastic product are replaced with similar but shorter
molecules, or if weather or sunlight or age can break chains in the
plastic, strength will suffer.  A plateful of congealed spaghetti
(without butter) will hold together better than a plateful of congealed
elbow macaroni.

Today's manufacturers are pressured to show that they are using
recycled materials, which in the plastics business in called "regrind".
It's already been extruded once, been chopped, reheated, burnt, and may
contain extraneous junk.  Its molecules are too short.  Now it becomes
part of your striker pneumatics.  It looks just like the previous
batch, but instead of the recommended less-than-ten-percent regrind,
it's maybe 25%.  Little molecular time bombs, waiting to make your
careful re-covering job fail in five years.

Determining the chain length in plastic and rubber is difficult.
There are certain tests, such as meltflow and instron, that attempt to
measure related parameters, but the best control is knowledge of the
actual practices that went into every step of manufacture.

Is anyone up to visiting all the possible manufacturers of rubberized
cloth and getting them to demand certifiable quality from their suppliers
of rubber coating material?  Is there a Mil Spec for rubberized cloth?
Who supplies it to NASA?

Peter Neilson