NOS
In this instance not the bottles of nitrous so regularly seen in fast and furious films, but instead New Old Stock.
Referring to a part that is (sometimes also NLA or No Longer Available) new and unused but may have been sat in storage for a very long time. Often packaging is missing or damaged but usually the part is in good order.
A while ago a 'lost' Volkswagen warehouse was discovered, In Paraguay and numerous NOS items were recovered.
See the VW Heritage blog article here: https://blog.heritagepartscentre.com/blog/2012/04/10/paraguay-reveals-its-private-parts/