John, I'm surprised that you are taking on the patty. I know it is probably the first piece of structure that you want to build and square away, but the way I look at it, you need to be confident in your overall size. And going by your question it seems that your not sure.
And with this in mind it is best to do your own work here as everything is interconnected. And you should be satisfied that everything else marries up.
When I look at Eagle1's super build thread, he started laying out the individual sections with kit parts and matching to photo references, like the upper and lower jaw box or docking ring arms. These help give clue to the real proportions. And he took several goes at it. It will unlikely be right first time.
This seems to be the traditional approach and a very good one. Whilst I have seen very little about it, I presume Mr Lee Malone did the same and the result is nothing short of amazing.
Only this way can you possibly start to determine the inner structure.
The easiest way is to lay out some styrene and start mocking it up, much the same as Stu has done. Use the kit parts as your guide.
Trying to start with the centre patty is a big leap of faith. Very rewarding if you get it right but otherwise....
I have spent a few years already on this process and I'm still a while a way from physically cutting something with confidence.
Per Searun's build, Andre and Joshua's drawings are a great starting place.
I have been trying to determine the dimensions of the core / patty for the last few months and I'm still unsure of several aspects that I am keen to resolve.
My current findings are not to diffrent from your detailed sketch.
I make the hull to be slightly larger at about 46.5" OD, 40.5 - 41" between docking rings, and shy of 7.1" across the docking ring face. And that 110° is probably closer to 108°. Difficult to tell with the armour plating.
Face it, if it was easy, there would be more of these things. As it's not just the fastest ship in the galaxy but the coolest hands down. Or Hans...
Do your homework, it will pay off.