Ancient China did not have Xerox machines. Paintings, calligraphies, maps, documents, etc made in the early dynasties would start to wear out from age and must be replaced. The Imperial System has a group of artists whose jobs is to reproduce as faithfully as possible the original documents. These reproductions are done by authorized craftsman and certified as authentic repros because they can be used as references for future research and official functions. The key to the 1763 document is the markings that indicate that it has been reproduced by an official and certified Imperial artists for the Imperial archives.
Ok and they only got one they bought off a street in shanghai. Ok it's real, you got me, The chinese were here first. You got your justification for the invasion. Have at it.
Goodness, and I thought they had 'Xerox Machines' way back then.