Hi Neil, that's coming along pretty well!

re:
> Is there some kind of mesh tool that can be used to do this better like the guy in
> the Rhino neck video?

What's the time index of this spot in the video?


> This was made using the network and lofting commands - so it wasn't solid - when I
> cut the top off - it was hollow! lol - how do I fix this? Thanks!

If the various Network and Loft surfaces are touching each other, you can make them into a solid by using the Edit > Join command.

Otherwise to work with surfaces instead of solids you could do an extrusion of your cutting side profile and trim that, similar to what's shown here:
http://moi3d.com/forum/index.php?webtag=MOI&msg=8822.14

Do you maybe have a version saved just before you did the cut? If so that would be good to see.

- Michael