Easy: just start paying back who is on the Nefario's list if you want be honest and consistent with your promise and past behavior. Who is not in the list, and say he should, can try his best to get things fixed with Nefario in order to get paid later, or just call the cops (the best option for everyone in this case imho). But using such cases as a pseudo-excuse to steal the assets of the most of your investors is just lame.
As you said, this process can only work if either Nefario or law enforcement is willing to participate in it. There's no evidence of either. And if law enforcement does get involved, the last thing an asset issuer will want to have done is paid out all the funds they hold to the wrong people.
I understand your frustration, but you are insisting other people do things that have huge risks to them and, frankly, don't make any sense. I would suggest pressuring GLBSE to agree to mediate a redemption process or, failing that, issue cryptographically verifiable asset holder lists so asset issuers can prove a particular person is or isn't on the list they got. You chose GLBSE to protect your ownership interest -- make them do what you paid them to do or hold them accountable.