A Russian poster on a discord I'm on actually spent hours tracking down what that was.

Turns out the book was recently published by sus publisher and is ghost written under the name Signature Unclear or smth.


Well, "Signature Unclear" is nom de plume of a small-time neo-nazi writer.
And the inscription in question was presented as an autograph inside the book by the said writer.


So not what it was reported as at all.