I've posted on this across many threads and figured it was time consolidate all this information into one thread. These posts will cover US made Gillette TTO (twist to open) razors only sold under the Aristocrat brand name, British or Brazilian varieties are outside the scope of this synopsis though I may post more on those later same with pre 1934 3pc Aristocrat varieties. The first TTO introduced by Gillette was the Aristocrat in 1934. From 1934 to 1940 they produced 3 variants of these as open combs in the US. The 3rd variant was available though not at retail level after 1940 still being sold to American Legion members as a special set through their emblem catalogs until 1942. From left to right the 3 variants produced from 1934 - 1940. Dates are approximate when they ended production of each. The first variant on the left was produced in 1934 and 1935 possibly as late as 1936. It is unique due to it's lower profile head than the rest of the variants. The second variant in the middle was produced in 1936 and 1937. The third and final open comb variant was produced between 1938 - 1940, the major change being the tabs standardized on all TTO razors in 1938 with the introduction of the Senator razor. Here is a picture showing how to tell the first from the second variant when you can't see the head profile difference. The key is to look at how the rivets affix the doors to the tabs.