It is presumably a Montblanc 310 (ident no. 13110) from the period of about 1985 to 1988 with a gold-plated stainless-steel wing nib, offered only as a cartridge pen with piston converter. Usually, however, the 310 has a cap with only one ring, while a double-ring cap belongs to model 221 (13121); here a mix-up apparently exists. Up to the early 1990s Montblanc was not a pure luxury supplier but produced, similarly to Pelikan, from school to high-quality models. Instead of an original Montblanc converter, a Pelikan converter is recommended.