Just as an observer i'd like to comment/suggest, why not simply put this whole thing to a forum/online vote for the contributors, and leave the vote open for a whole month to allow people sufficient chance to catch it.
Everyone who has voted could be I guess listed in the new licence document, to state for the record, that these people voted and that the vote was open between these dates (maybe other thing to consider, is also list all the people who were emailed/forum contacted too).
Just a thought, and maybe something like this is logistically manageable