[turretslug]

I recall bales of that packing stuff around Dad's garage as a kid- cast-offs from packing military kit of every sort in its sturdy cardboard boxes or wooden crates. I agree with M0FYA Andy that it seemed to consist of congealed latex binding some sort of stiff, resilient hair, holding it all together as a strong and probably very effective protective material. A distinctive smell, not unpleasant but no rival to eau de cologne! As can be imagined, it burned well with a truly horrendous smoke, and that makes me pretty certain that there's no asbestos or other mineral fibre involved.