The imprint “Metal France” on the clip is nothing to worry about in itself. For a time Montblanc had certain overlays made by Cartier, which is where the French mark of origin comes from; it is found on some Bohème pens among others, while most pens carry “Germany”.
The papers that come with the pen are another matter. If the service guide shows a model that never existed — a “StarWalker Bohème”, say — that points plainly to a fake, since StarWalker and Bohème are two separate lines and were never combined. Nor does an engraving voucher belong with a model such as the Carbon Steel, whose cap offers no surface for an engraving at all.
A sound judgement cannot be reached from a verbal description alone, because by now it is not only the pens themselves that are forged but serial numbers, certificates and service guides as well. In case of doubt the only remedies are to show the pen to an authorised specialist dealer or to have it assessed from sharp, well-lit close-up photographs of the clip, the cap ring, the nib or push-button, and the refill housing.