And for those who are wondering, I already gave Doug my advice on this topic, which is: Buy the CDs or find the MP3s on a filesharing site. I don't think there's anything worth the amount of trouble you'd have to go to in order to do the cassette-ripping task. I shudder to think the amount of work and hassle this is. I can understand the need to do cassette rips only if the songs are unavailable in any other way.
So he's already heard that particular advice, you don't need to give it to him again.

Side note: I think this is one of those situations when finding the MP3s on a filesharing site is perhaps justified. Not *legal*, but justified. You already own purchased copies of these songs, you just want to play them on new devices.