I suggest you to start with the structure of the command tower before building the skin: the main quadripod should go from the main deck to the upper range finder: start with that and build the main tower around it: it will help you getting the whole thing together and will save you a painful alignment ordalia.
Also, avoid those kind of bands I see marking the floors in the main tower: they were not present in the real ship: It looks like the idea is coming from HobbyBoss 1/350 which has so many faults to make it unworth of building
viewtopic.php?f=59&t=152675.
Check this project to better make sense of what I'm telling you.
I strongly suggest you to find some decent blueprint for the ship if you really are going to start a new build in 1/72.
THIS is a good place where to look.
"For the one who walk in darkness with a stick is blind, but the one who sticks out in the dark is... Fluorescent!"