A legal "hack" could be to setup a liability limited company that violates the copyright on the AmigaOS 2.x on record. Then see who will sue and challenge in court to have them prove their legal ownership. If no one sues, then statute of limitations should make the case expire and subsequent cases void.
Another approch is to write to the Copyright office and ask for any information regarding the chain of title.
I'm not sure that statute of limitation really applies.
"Note, however, that limitations periods may begin when the cause of action is deemed to have arisen, or when a plaintiff had reason to know of the harm, rather than at the time of the original event."
They could sue for future losses caused by you breaking the law now & the date of the future loss could be when the statute of limitations clock starts ticking.
The copyright office doesn't necessarily have to be aware of the owner for the copyright to be valid. Berne copyright convention doesn't require registration of any copyright.
Basically there are no short cuts. You could do what the old commodore did, break the copyright but put money aside in case they come knocking for money. Then settle out of court with the royalties. You'd need to put quite a bit of money aside though.