Montblanc built the pencil of this anniversary edition as a twist pencil: the lead is advanced by a twisting mechanism, not by a push button. Where such a piece is offered as a push-button pencil, it is almost always down to the seller's lack of knowledge and not to a second version existing. The pencils of the Meisterstück line are traditionally twist pencils in any case.
A warning sign of quite another kind is where the photographs in the listing come from. If the pictures plainly originate from collectors' websites or dealers' catalogues, the listing is not showing the pen actually being sold. Quite apart from the question of copyright, it means that the buyer has no way whatever of judging condition and authenticity before parting with his money. In such cases one should insist on additional pictures that are unmistakably the seller's own and that also show the nib or mechanism, the engravings and the cap top.