Regarding Blackhawk: Were the Copyrights owned by Mrs Arnold transferred to DC (there should be a record of this somewhere, if not online, then at least on-file at the Copyright Office)?
Just want to amend this statement. After reading a little more, it looks as if all DC would have to do is prove that they are the legal Copyright Owners. From what I understand, it isn't mandatory that this "proof" be recorded at the Copyright Office
(especially for the issues that were renewed by Clare Arnold), only that a legal document exists that proclaims that Clare Arnold passed ownership over to DC at some point.
To clear something up real quick: An "Orphaned Work" is not the same thing as "Public Domain". In the case of Orphaned Works, it has to be shown that an attempt has been made to determine & contact the legal Copyright Owners before reproducing the work in any format. As far as this site is concerned, my opinion is that Orphaned Works have a place here, as there would be no legal owners of the books who would be able to reproduce the material for the mass market.
From what I've read, it looks as if there's a limited amount of time DC has to take action (I assume from the date the files were created) IF they were the legal Copyright owners. DC would not be "abandoning" the Copyright, IF they are the legal owners, based solely on the fact that they have not taken any type of action against GAC, but after that period of time has passed, they would be unable to start a "Criminal Proceedings" or "Civil Action".