Just had a thought pop into my head and haven't looked into it at all yet, but is it possible via VBA or lisp to read a CTB? VBA would mean a lot fewer questions from me.
We get and use titleblocks from clients a lot. A large percentage of them plot fine, as is, with our pen tables. Some, not so much. I was thinking about a program that read two CTBs, selected by the user and changed layer/entity colors from one to a similar color in the other.