Updated 7th September 2017
Just a few pictures I found online:
- All wrappers are marked in Danish , or possible Norwegian.
- The orange wrapper is 50% more expensive than the blue, possible because it’s guarantied Swedish steel and have a hollow ground. Chef is the Danish (and old Norwegian) way to spell Chief, as in department head or leader.
- The blue and green wrappers held blades of “control grounded electro-steel”.
- The green wrapper is marked as a new model with a slot.
Late 30’s I would think, based on the spelling and graphical design… not the early 40’s, considering the War. Possible late 40’s if they are Danish… written Danish and Norwegian are fairly close, and was closer back in the day. Å became an official letter in Norwegian in 1917 (replacing AA in most instances), but not before 1948 in Denmark… so that would indicate a Danish blade. But nothing is ever easy when it comes to Norwegian orthography; the use of AA continued in ‘Riksmål’…
I think it’s possible that the air-plane is supposed to evoke a DC-6 (in production from 1946) or a DC-4 (in production from 1942) – both were in use as passenger aircraft in Scandinavia after the war – which would place these blade wrappers in the time period between 46 and 48.