Converting multiple surfaces to solid for STL export

I'm in the process of moderling a knight chess peice and I have started with a revolved base and lofted the body throught a series of sketches and a seprate surface loft for the head. I am currently running into problems converting all the induivedial intities into a single solid for exportation to STL for 3d printing. The bottom image is an example of the g-code. This is the file https://www.dropbox.com/s/n6dlubt7qmldnxr/semi%20final%20knight_working.SLDPRT  I've also attched it.

Thank you Nic

SolidworksSurfacing