Loving your Parenti-series of posts as of late! For anyone that hasn't read or listened to the late Michael Parenti before, I highly recommend the "Yellow Parenti" Speech on US interventionism, the third world, and the USSR and Blackshirts and Reds | Audiobook. His lecture on "Inventing Reality" is also excellent.
For more works on the general question of reform vs. revolution, I recommend Rosa Luxemburg's Reform or Revolution | Audiobook, as well as Lenin's The State and Revolution | Audiobook.
For learning about Marxism-Leninism in general, I recommend my intro ML reading list.