As information:
The Cosmophone 35 and 1000 were true transceivers. In fact they had what would today be called "dual VFOs" and could operate transceive on either VFO or split, by means of a simple selector that determined which "VFO" controlled receive and which controlled transmit.
In reality, there was only one VFO - but it had two tuned circuits, selected by a small relay inside the VFO box.
What makes a radio a "transceiver" in the modern sense isn't whether it has everything in one box.
What makes a radio a "transceiver" in the modern sense is whether it is an integrated system that permits the receiver and transmitter frequencies to be on the same frequency without having to adjust separate frequency controls.
Having an external power supply does not mean a radio isn't a transceiver - if that were the case, very few of the HF transceivers made for the amateur radio market would meet the requirement. Almost all of them (including the National NCX-3, NCX-5, 200, the various Hallicrafters, the Heathkit SB/HW lines, the Drake TR series, and many many others) had external power supplies - yet they're all transceivers.
The "wattmeter wars" of the 1960s were a real thing. Early amateur HF transceivers were what today would be called "100 watt" rigs, usually using a pair of 6146s or horizontal deflection amplifier tubes (aka "sweep tubes") to provide about 100 watts CW output and SSB PEP output. Some provided a little more. That power level was more than enough to drive a grounded-grid linear amplifier to the legal limit.
Some manufacturers decided to go a step further, however. Swan had their popular 350 and 500 transceivers, Hallicrafters had the SR-400 and SR-2000, Drake had the TR-3 and TR-4, Yaesu with the FT-DX400 and 560, and of course National. Even Signal One got into the game a bit. All ran more power than the usual pair-of-6146s "100 watts" - some a little more, some a lot more.
There isn't a clear "winner", though.
The Hallicrafters SR-2000 could run the old US legal limit on SSB (2000 watts PEP input) but on CW was limited to 900 watts DC input despite having a pair of 8122s in the final amplifier.
The National NCX-1000 could run the old US legal limit on CW (1000 watts DC input) but on SSB was limited to 1000 watts PEP input to its single 8122 in the final amplifier.
The advantages were obvious - fewer adjustments during tuneup, smaller overall size, hopefully less overall cost. But there were disadvantages too. Besides the generally larger size and weight (the NCX-1000 weighs 60 pounds), the power requirements tended to rule out mobile and portable operation compared to "100 watt" rigs.
All of this is easily verified by looking at the rigs, their manuals, and the dates of production.