The first piece is a Meisterstück 744 (production 1951 to 1956); on imprints 585 or 750 on cap, body, clip and end cap it is solid gold, otherwise gold-plated; an initial engraving reduces the collector value. The second piece is a Meisterstück 132 from the 1930s to 1940s, with possibly a subsequently applied overlay; only pieces with imprint 'Montblanc' or 'S' (for Sarastro/Pforzheim) count as official and collector-coveted overlays. Nibs of old gold pens Montblanc itself cannot exchange; corresponding orders go to external specialists like Horst Schrage. For old writing instruments the water-soluble Pelikan 4001 royal blue is recommended as the most uncritical ink, since black and strongly pigmented inks can discolour the ink window.