I found these two in my grandfather stuff. These must be dated 1920-1940 since after second World War he was using doubled edged reusable (so my father says).
Can anyone tell me anything about these, why the blades are so thin (used?):
http://www.imagic.pl/files/1706/thumbs/1side.jpghttp://www.imagic.pl/files/1706/thumbs/2side.jpg