Acronym for "new old replacement stock," or "new old reproduction stock." These are parts that were aftermarket replacements, usually of the same quality, for the manufacturer's parts. Or, they are parts that were reproduced by an aftermarket supplier using the same quality of materials and manufacture as the original manufacturer, but now are "old."
NORS
Meaning of NORS in English
English dictionary of automotive terms. Английский словарь автомобильных терминов. 2012