Tintin on the moon - 3D rocket model

I just finished the 3D model of the rocket from “Tintin on the moon”.
This is quite simple but it took me sometime anyway.

Any idea on how to improve it?

As well, you can use the blend file freely.
You can find it on my blog: http://renderedbyblender.blogspot.fr/2013/09/tintin-on-moon-3d-rocket-model.html