For older writing instruments, exclusively water-soluble ink such as Pelikan 4001 royal blue is recommended, since other inks can clog the feed or discolour the material; red inks are particularly aggressive. As entry-level models the Meisterstücks 142, 144 and 146 from the 1950s are suitable, as well as the models 252, 254 and 256, which are uncomplicated and everyday-suitable and mostly cost under 400 euros. Repairs are carried out by specialist restorers like Horst at maxpens.de or Penleo; Montblanc itself can replace some parts but not remake nibs, since for that its own moulds would be required. When buying, attention should be paid to nib width, the existing iridium tip and cracks in caps. Push-fillers leak more quickly, which is why piston pens are more everyday-suitable.