New Old Stock - ah yes, perfect, unmolested, parts for your vintage car or whatever else you need replacement parts for.
If only it were so easy. It seems, however, that there is new old stock and then there is new old stock.
Many buyers will accept that although an item is unused and still in original factory packaging it may have some very light shelf wear, just from sitting around in a box for 40 years. Furthermore, although these are essentially new parts, they may not have been finished to the quality standards that buyers currently expect and therefore may require refinishing.
Larger items, particularly body parts, are more succeptable to damage. Thus you may see new old stock sheetmetal with minor dents or even light surface rust, due to storage conditions and the sometimes poor quality of factory primer.
All this said, the next time I see someone on eBay listing an item as "new old stock" when it's had a few dents repaired, been sandblasted and then been primered with a rustproof paint, I just may scream. Is the item "like new"? Probably. But "new old stock"? No.
Then again, maybe they're all just trying to get more people to view their auctions.