need help putting a date on blades

[jflwr]

Picked these blades up a while back and was hoping someone could help me put a date on them. Any info would be much appreciated!

 

[mblakele]

http://mr-razor.com/Rasierklingen/Rasierklingen.htm has a similar package with the same price, from 1961. However the packaging was much the same from 1940s to 1960s. To be certain of the year you would have to open up the package and read the date code on one of the blades.