The problem is that you’re not actually “showing a book to be made up of lies”, what you’re actually doing is saying that a few parts in the book are lies while implying the rest is true.

If, in the process of pointing out what is false in the claims about the Lenin period, you are explicitly contrasting it with what came after to say that the bad things actually only started to happen later, you are validating false narratives which are in essence no different to those that are used to discredit the Lenin period.

Making the concession “sure, Stalin bad” is the first step to conceding that Lenin himself was bad, because it is very easy to show that there was continuity. Stalin was a student of Lenin who continued the process of socialist construction that was started under Lenin.

I’m afraid you don’t understand how anti-communist propaganda works. The point is to get you to concede that at least some of what they say is true, which they can then use to say “see even the communists admit socialism was tyrannical”, which is then used to get a foot in the door to push for more and more concessions until you end up denouncing all socialism. The next thing you know you’re constantly correcting people about how you’re a “democratic socialist”, not one of those evil tankies who support “authoritarian regimes”.

There is no reason whatsoever to throw one of the most important and successful periods in socialist history under the bus just to ingratiate yourself with liberals. That is pure opportunism. It is perfectly possible to make the exact same point about how Solzhenitsyn is full of shit and peddles lies without conceding to anti-communist propaganda.