Marvel was always an administrative mess, repeatedly going bankrupt. Its deals with its creators were indifferently papered over, and then Marvel lost a *lot* of the paperwork. I'd bet anything that many of the key documents Disney (Marvel's owner) needs to prevail over Lee and Ditko are either unlocatable or destroyed - or never existed in the first place.
53/
A more muscular termination right - say, one that kicks in after 20 years, and is automatic - would turn circuses like Marvel-Lee/Ditko into real class struggles. Rather than having the *heirs* of creators reaping the benefit of termination, we could make termination into a system for getting creators themselves paid.
In the meantime, there's Willingham's "absolute table-flip badassery."
54/
