The Meisterstück Classique with gold-plated trim and the ident number 106514 is the 145 fountain pen, the smallest model of the classic Meisterstück range below the 146 and the 149. Montblanc once listed this model under the name Chopin; the name was later dropped in favour of the plain size designation Classique.
The small coil spring lying loose inside the clear piston converter is not a fault but deliberate. It breaks the surface tension of the ink: without it, ink can cling to the rear end of the converter as the level drops, so that the pen stops writing although there is still a supply in it. There are converters without this spring as well; they are more prone to the problem.
Current models do carry a serial number, it is merely placed discreetly: it is laser-engraved into the upper ring at the clip and consists of a sequence of letters and digits. Only Montblanc itself can read and trace this marking; for owners and collectors it serves above all as a mark of authenticity and identification, not as a date of manufacture.