I think the jury is still out on this issue. I have been following Regent Tech sets over several years now and about 7 out of 10 had the "aristocrat" razor , with the uncovered carriers on the side. On the other hand, some sets, including the one shown in Krumholtz, have the Senator razor in them. Unfortunately, I am not a ware of any adverts that present the Regent Tech. It is interesting to note, that the 1946/7 Aristocrat sets came with instructions describing them as "Tech Razors", suggesting a link to the Regent Tech.. AsylumGuido's theory also makes sense.
Thanks, Arik. I have been pondering this for awhile, but this just brought it to the forefront. I have also noticed that very instruction sheet reference. That is what really convinced me. I wasn't going to bring it up until I could find any advertising reference for support, but I have not had any success.
It just makes too much sense that Gillette would promote the three first solid guard (like their establish Tech) TTO's in 1941 as the Ranger Tech (basic nickel plate), Milord/Milord Tech (basic gold plate) and Regent Tech (upscale gold plate) in this manner with a Ranger and a Lord and a Regent having increasing influence respectively in society. This also fits the 1946/1947 introduction of the Aristocrat. Note that the earliest post-Ranger Tech Super Speed was marketed as an Aristocrat Junior, or a step down from Aristocrat.
As for the Senator/Regent Tech connection, I can see Gillette taking the New Improved approach to get more mileage out of the same razor by marketing it in different cases.