I think most if not all guys are either flex instructors or check airman. There are still a few retired Fed Ex and United pilots that keep current in the DC-10 and fly a few trips a year. I don't think there is any official sign up list, probably just need to talk to the senior check airman that do it.
They will probably need MD11/10 typed guys when the new DC-10 that United just donated gets converted in 2010 (the last MD10 conversion on the line)
I hear it is very rewarding.
