747 Overhead Panel Measurements/Diagrams Request

Was wondering if anyone knows where I could find measurements and diagrams for the 747-400 overhead panel? I'm attempting to create a 3D model in my 3D program. I've started modeling part of the overhead panel using the PMDG 747 as a reference photo but after thinking more about it, I want to model it to scale. Eventually, I would like to model the whole interior of the 747-400 cockpit but for now, I'm starting out with the overhead panel. I may post a pic of what I have done currently when I get home.