My dad was about to throw his old CD160 out when I said 'I'll have that thankyou'
I've just spent an hour replacing the rectifier diodes with MBR1100 Schottky diodes, removed the opamps, replaced them with sockets and plugged some LM4562 opamps in. It sounds rather good. I fed the analogue and digital outs into my MF KW250S and toggled between them. OK, its not as good as the KW's DAC stage but it didn't disgrace itself.
I'm sure there is a lot more that could be done, but that will do for now.