The only change from the original is that I used MeshLab to remove the support within the nozzle. It seemed like it was causing problems for a lot of people, me included, when not printing at 100%. It now slices correctly in Cura printing at 50% scale (about 100mm tall for main body) with supports set at "Touching Buildplate" and other support settings at the default.

You can find the rocket's nose and other optional parts here: http://www.thingiverse.com/thing:427789