In 1909 Gillette presents these new line of models, the "Pocket edition".

Without any doubt, the most beautiful line of razor sets ever seen before (at the moment) for all public.

One interesting information is that in 1915 the safety razor handle was re-designed, loosing its ornamental lines, probably to make the manufacturing of this model cheaper, trying to keep the same popular price than six years before. On December of 1915 we can find an advertising on "The saturday evening post" where it is called "no 501 Basket Pattern Pocket edition" and probably the first time that it is announced on paper.
This is the introduction of the regular "old type ball end", we can see it in the 1916 models for the U.S army, using the same name than the older pocket edition staff, announced as "U.S service set" on 1916, or "pocket edition 501 / 502" on the catalogue of 1918.