I would try to fix the repos in /etc/apt/sources.list and /etc/apt/sources.list./* and upgrade manually, but the info you give is a bit space, so I do not know the state the system is in. The post scripts migrate the database, which may not happen, if you update manually, so you may have to to it manually too.
Fixed the duplicate repos and tried run-parts through the run.d scripts (in hopes of a simple repair) but no upgrades occured. Guess it's off to search on the manual upgrade process. Thanks for the pointers!