i used halo wiki and just used alot of different pictures to try to get the proportions right as for the interior, your guess is as good as mine.

Is this full scale? if so; how did you figure out the proportions of each component of the ship?(i.e. the dimensions of the engines). I'm trying to build my own and I don't how where I need to put what. :/

ill try cant find the photos

could you post more pictures of the ship it looks cool