From what period does a Montblanc 146 with solid-gold nib, completely transparent ink-view window and only 'W.GERMANY' embossing on the clip without serial number come?

This feature combination points to a Montblanc 146 from the 1980s: at the time, solid-gold nibs were fitted and the ink-view window was completely transparent without stripes. Serial numbers were only later laser-applied to the clip, which is why the absence of a number in this period is normal. If, on the other hand, on a nominally older piece a serial number is present, this can indicate a later cap exchange.