The absence of a serial number is no indication of a counterfeit, since Montblanc introduced serial numbers only relatively late; counterfeits today often even bear fictitious numbers. A 146 without platinum intarsia on the nib usually indicates production in the 1980s. The clip engraving 'W-Germany' stands for manufacture before reunification 1990, 'Germany' for later production. Further detail features can be compared via the historical model descriptions on fountainpen.de.