I started a second ship today after being given some new tools to work with in Maya. This was what I wanted to copy the look of:

With a refresh on the add edge loops tool along with tuition on mirroring geometry, the cut tool, vertex welding and booleans, I set about trying to emulate the look of this ship. Using the top down concept art to rough out the shape using extrudes, this is what I have thus far:
After a peer review/scrum, a few warped faces were found that would have caused issues with rendering/texturing and also a couple of n-gons, which have now been fixed.
UPDATE
After putting more time into the ship this is the end result:
The guns were modelled as a separate object and then combined with the original mesh and welded into place. The engines were added using a standard poly cylinder and a boolean, however this did create a lot of unwanted geometry. I decided to stick with it and put the time into cleanup rather than find an alternative.
This was a huge improvement on my previous model, but I had issues with topology flow and getting overwhelmed by using too many polygons. Lessons to be learned are: better forward planning to deal with topology and to spend more time on clean-up to remove unnecessary polygons.