Kharkov design bureau was paid to develop next gen tank, and in mid-70s they have pursued two designs simultaneously, more traditional one - 480, and some other design with unconventional layout.
That's established by the documents (published by Andrei_bt in his tg channel)
Which unfortunately do not give any description of unconventional layout.
But judging by text of Morozov Sr.'s diary, and by notes, attributed to Morozov Sr., about evolution of obj.450 design in 1972-1973 -
In 1973 obj.450 have arrived to layout very similar to one used in late 80s for obj.477A (hull ammo compartment between turret and engine, fully automated; and second autoloader for several rounds in turret basket), and as 477A is a >50t tank, that means that even with smaller gun and ammo and armor, that Morozov's next gen tank, weight-wise, have arrived to - not exactly the same point from which it started in late 60s, with conventional ~42-44t modifications of T-64A, but very close to it.
Which is why Morozov went on to search for another, more promising, layout. And not just by himself, making that sketch and providing description of it, but also by assigning some people from Kharkov design bureau to its development, and making presentations - in 1975-1976, final years and months before he retired.
(It's just one of many things which Kharkov bureau was developing simultaneously - there was T-64B, 476, 480, and 450-as-two-man-turretless-tank on top of that).
It's currently unclear, how much that contemporary scalemodel, in first message of this thread, resembles that turretless two-man tank which was presented by Kharkov design bureau during any time of 1975-1976,
as, according to diary, such design have changed over time -
I'd like to remind that there were at least 4 different layouts of 450 in 1973-1973 alone, and some changes were still happening to turreted version of it in April of 1974.
Or any other tank developed by Kharkov.
According to yet another document (one page posted by Ansrei_bt in his tg channel),
research program Sodruzhestvo ("Unity") for main battle tank of 90s, from late 70s (previous research program have ended in October-November of 1977, this one is mentioned in February of 1979) have studied 3 layouts, without giving any details. Andrei_bt, while posting this page, have described 4, including - separately - 2-man tank and turretless tank. If that's correct, that adds entire 1978 to study more versions of that layout.