Late Stage Capitalism

Yep. Chuev conducted a series of lengthy interviews with Molotov over the period of 1969 - 1986 and he kept extensive notes about what Molotov attested to.

While I can't seem to find an English language translation of 140 Conversations with Molotov, his other work, Molotov Remembers, is frequently cited as a primary source by historians.

Given that it's testimony from something which was said many years prior to the interview I'd hazard a guess that Molotov was paraphrasing because the chances of it being an exact quote are vanishingly slim but such is the nature of historical work; often the eyewitness testimony is going to be somewhat hazy, especially long after the fact.

I personally would feel comfortable in saying that Stalin had actually said something to this effect, if not exactly word for word, to Molotov.