Such unusual products are generally not made by Montblanc itself but by commissioned third-party firms that either produce exclusively for Montblanc or only apply name and logo. Therefore, these pieces do not have a special manufacture-related value, since they did not arise in the Montblanc manufacture. A certain collector value they nevertheless retain, because they officially belong to the brand world. Whether a particular concrete piece, e.g. from an auction, is original should be checked case by case.