Interesting paper on the early years of DE razors and Gillette:
http://www.law.uchicago.edu/files/file/Picker paper.pdf
http://www.law.uchicago.edu/files/file/Picker paper.pdf
"King C. Gillette, the man and his wonderful shaving device" by Russell Adams is a fantastic read for anybody interested in this sort of information.
What multiblade razors was Gillette competing with in the 1920s?
I may have stumbled into the wrong term. By that I mean other firms selling multiple blades with the possibility of disposability. The Ever-ready and the Gem Junior are good examples.
Does that clarify?