letter scale
This combination of a letter opener, letter scale and ruler, does not have a maker's name. It does show an advert for Canadian Club. The scale strongly resembles the scale as shown in the figure of an American patent from 1968. This patent with number US 3,365,011 was granted on January 23 1968, to John Heil from Dayton Ohio USA. The congeniality with patent number US 2,612,365 from 1952 of Nielsen, from Denmark is already mentioned in the text of the patent. See the Linex scale for some additional information. This Canadian could be from a date more recent then 1968. Below some more pictures of this scale.
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