I think what HJ is getting at is that the mechanism is fresh from the box, and that the entire loco was mint in box before he started his process. Completely agree that it could be better worded, however.
It begs the question though, if a loco is purchased new and sent to a professional for a respray/weathering, is it no longer new? It is clearly no longer mint, but new? Has it ever turned a wheel? By ebay's revised definitions, HJ's locos should certainly be listed as used - as should most of the 'new' locos which have "only been test run".