Could you look at these sentences:
"Somewhere else in the fanzine I mention that I'd written to the Nivens and sent a tape and asked them if they'd be so kind as to fill it up with more of their groovey songs! Today I receive a tape."
I don't understand the use of past perfect for write, send and ask as the events are in chronological order.
First he wrote, sent and asked then he received.
There is no need of past perfect here.So did the author choose this tense to emphasize the gap between the time he wrote and the time he received it. He surely was not expecting to receive an answer anymore when he got it.