Hi Julian,
Of course, you are correct re: A&R DIN pins 3 & 5 being input. My comment about pins 1 and 4 (now removed) were in relation to using the A60AP as pre-amp, rather than the pre-amp section of the NAD; in which case an old Frietag (remember those?) 4 x RCA to 180º DIN tape interconnect would do.
On the NAD end, as with 3020, 7020 has 'pre-amp out' and 'normal in' sockets connected via U-shaped links. Were it a 7020e he'd need go tape out from the receiver.