As ever, in the world of Antiques, your primary protection is the integrity, expertise and reputation of the Dealer. Having spent many years in the map and print trade, we have rarely encountered anything that approached a forgery. It is perhaps the feel of the paper, the crispness of the printed impression that distinguish the genuine article. Whenever possible, Postaprint provides a photostat of the Title page of the Atlas or Book from which the map or print came. Modern reproductions are of course on the market, but these are normally quite recognisable as such, indeed are so modern in appearance as to be readily distinguished from an original.
Restoration is another matter.
So much antique furniture has been restored or 'married' over the years, that to find a piece in truly original condition is becoming quite rare. Some antique maps may have had minor repairs carried out to, say, a slightly torn fold. When the potential fragility of maps is considered, it is remarkable that so many have survived in good condition for over three or four hundred years. We can but admire the quality of the hand-made paper on which they were produced and the splendid binding of the early 'Atlases'. Apart from those manuscript maps and charts produced on vellum or parchment, most early maps which we are likely to find were printed on strong, thick hand-made paper from France, Germany and Switzerland and the finest of all in the Ancona area of Northern Italy.