Very early in the 20th century, Christian Olsen, a Danish businessman acquired the sole rights to import Parker pens into Denmark. Parker were very keen to establish themselves as a global brand and went on to establish agencies in many European countries as well as in Canada and South America.
By the 1930s, trade restrictions forced Parker into giving Olsen the rights to manufacture and assemble Parker pens at his factory in Copenhagen under licence. As time went on the Olsen company gained in independence and added some refinements and slight differences to the pens, including some colours that were not produced elsewhere, including this shade of green and the burgundy on the twin jewelled Duofolds in the photos.
Olsen had a strong connection with, and interest in, things of a nautical nature and devised the 'anchor logo', which included the initials 'CO' and an anchor inside a circle. It is imprinted on the barrel of this Duofold, later pens did not show the logo but were stamped 'MID' For 'Made in Denmark'.
In 1946 the hugely successful Parker Duofold was drastically redesigned to produce the 'Duofold NS', New Style. It was manufactured in the U.K. But Olsen produced a Danish version of the pen. Very early Danish pens featured a 'Split Arrow' clip with 'Parker' inscribed longitudinally. These pens, now known as 'first generation' Danish Duofolds' are all 'Senior' sized.
The Danish Duofolds, particularly the first generation pens, are rare and highly collectable.