As a labour of love, I've spent about 80+ hours going through this model with a fine tooth comb (as well as Magics and Netfabb) to fix this model and make it more printable.
Included versions so far are:
Ship with no panels and merged shuttles
Ship with merged panels and merged shuttles
Ship with separate panels and merged shuttles (zero clearance)
Ship with panels separate and shuttles separate (with clearance)
I've merged all the shells, fixed all holes, extruded all really thin pipes into the main body, and cleaned up a lot of problems. I also added the shuttles which were missing, and removed the covers on the engines to show the internal blades.
This is based off V4 Serene Firebug (Hi Poly) Firefly Serenity as it had more information to allow fixes to take place (V5 was a mess).
With over half a million triangles, there are no holes, overlaps, or intersecting triangles. This should be easy to slice and print.
Stay shiny and keep flying!