Well. Downloaded the rar from the russian site (thanks for the link!!)
It looks real, I think it's real. But I guess the original tape was such a low quality.
9.flac (M9)
11.flac (Whitewater / One Very Important Thought)
In short:
Lossless files have frequencies that extend all the way up to 22 kHz.
But it depends on the genre and on the source too.
(Good comparison here about a
pop and a piano song)
So, even though the audible data is way below 22khz on both files, you can see the white noise extends up to 22khz.
No cut off.
Which means all the data has been recorded (= lossless).
But the source was not a good quality (= cassette tape).