I too am curious and am no better at finding this logo online than you are, apparently ;)

In case anyone is interested though, here are other logos that Paul Rand has designed: http://www.paul-rand.com/site/identity/

Amazing how many iconic logos are on that page.

Jobs paid Rand $100k for the NeXT brand identity, and Rand created a 100 page brochure detailing the brand.

Jobs on working with Rand: “I asked him if he would come up with a few options, and he said, ‘No, I will solve your problem for you and you will pay me. You don’t have to use the solution. If you want options go talk to other people.’”