I documented some of their edits here: https://hexbear.net/comment/3599050

It’s because of trickery such as this that we decided that on the prolewiki library we would not edit texts from the original.

Note that Mastering Bolshevism seems to be the title marx2mao gave to these two speeches collected from Stalin, a more common title is indeed the one marxists.org uses.

Anyway, you can request an account freely on prolewiki and then use it when you feel like it or when you have time. https://en.prolewiki.org/wiki/Special:RequestAccount