About the two sentence constructions you presented for grammatical analysis:
(1) "Lenin had lived in Europe for three years at time of the workers' uprising in czarist Russia. He was then hurriedly ushered into the motherland by his followers to lead the October Revolution."
The first sentence correctly uses the past perfect tense in "had lived in Europe" but is marred by the absence of the article "the" in the phrase "at time," which should correctly read "at the time." This looks to me simply a proofreading error, though.
(2) "I had lived in Africa when as a boy, but that was ages ago and I have not the remotest remembrance of what life was like then."
This sentence deftly combines the past perfect in "I had lived in Africa" with the present perfect in "I have not the remotest remembrance" and with the past tense in "what life was like then." This sentence construction clearly indicates that the speaker is talking at the present time (now) about the fact that he had lived in Africa as a boy (past perfect), and is declaring that he has no clear recollection (present perfect) of what life was line then (simple past). There's a minor grammatical wrinkle in that otherwise well-wrought sentence, though. The phrase "when as a boy" looks and sounds garbled in the absence of the words "I was," which I suspect were inadvertently mangled in transcription. See how much more smoothly that sentence reads when the phrase "when as a boy" is corrected to "when I was a boy":
"I had lived in Africa when I was a boy, but that was ages ago and I have not the remotest remembrance of what life was like then."
Another fix for that grammatical flaw in the original sentence is to simply drop the conjunction "when":
"I had lived in Africa as a boy, but that was ages ago and I have not the remotest remembrance of what life was like then."
