For the baseplates not the knurling and with that said they should shave the same as the 80s versions. Never had one between 78 and 80 so can't say for sure.
At first I thought you created a Frankenrazor! I've never attempted to take apart a TTO, but I assume you can switch handles if you are machanically adept.
Different markets and in turn different focus group results which leads to different tooling and dies to make the razors.
Like most of you, at one time or another I've owned or handled every basic type of American Gillette that they produced. After the Knack/Slim Twist, this one I've used the least and kept the shortest amount of time, if one happened to show up in a lot. Can't count how many I could have had for peanuts but walked on by. Will it shave? Yep, but it just seems light, rattly, cheap, and unexciting when next to, say, the 1958 TV Special or even the venerable 1940s classic. But what do I know, I like old zamac razors.
1. the original - 1966 to circa 1978 2. square/flat-bottom baseplate - circa 1978 to circa 1980 3. square/flat-bottom baseplate with different knurling on handle - circa 1980 to 1988 4. Not sure what other changes Sqare baseplate shaves different than original?
1. Diamond baseplate, square knurling 2. Square baseplate, square knurling 3. Square baseplate, diamond knurling 4. German made model with smooth TTO knob.
Yeah, you have Argentine, U.K. made for the French market, and German made TTO Gillette razors (outside of the common U.S. and U.K. variants). There may be Mexican and Brazilian made as well, though I cannot recall if those were techs or tto's.
Brazilan Gillette razors are a whole breed to themselves especially their goodwill variants which are based on new short combs not new long combs like the US and UK versions.
These 2 look different to my eyes. Both are different than the late 70s-introduced "rectangular" one. Is it a 5th variation? Square baseplate: Mine from 1970 is like the one in the first pic. Is it worth trying the others -- different shave? thanks