Have you watched Ed's video? I'm not sure if it will answer your question or not, but it can be pretty informative. https://www.youtube.com/watch?v=ZTMgZ7jsj6E
As far as sealing the overhead console to the baggage bulkhead, I got some weather seal from McMaster. I used p/n 8507K15 from them. I left a small gap between the console and the baggage bulkhead. Then used soapy water on the Mcmaster seal to slip it into position.
That's just how I did it. There have been many different things people have done to seal that area.