Rhino + Guitar curves

Hi,

I just downloaded Rhino again to try and build a guitar body in it. I am
almost toally new to it in comparison to most of you guys. I started by
drawing a set of curves on the front veiw to create a contour, then joined
them and extruded out the shape to the correct length of the body. That's all
fine. Then cut out the pockets for the pickups, bridge, neck etc. Easy.

From there I needed to profile the edges of my contoured block (Top and
bottom contoured only so far). I guess I kind of cheated here rather than
finding out how to do it properly and used the fillet tool with a massive
radius set to create the first simple curves at the back end of the body. I
now have a top and bottom contoured block with a rounded end (The end furthest
from the neck).

And now I'm stuck! :P I was working through the tutorials, my duck was
going great till it came to trimming the extruded neck into the body. Dumb
duck! Click inside the body inside the extuded area? I think not! Being new to
it I kept pressing F10 with my guitar body to try and get control surfaces up
to profile the kind of figure of 8 shape most guitar bodies are, but alas 'Can
not use control points on polysurfaces'. I also kept trying things like using
trim to cut the body profile but the cutting tool, my curvy line, doesn't seem
to want to do much cutting (Would I create the curve in top down view then,
anywhere vertically above the body, then use it to cut through?). Could I use
the curved line as a cut plane? Another idea was to create a curve, extrude it
down, extude it back, then use the difference tool to cut the shape into the
bodie's side. But there must be an easier way than that judging by how much
easier other things are in this! So, any help with this would be majorly
appreciated.

My second problem was... If the body is contoured on both sides how could it
be machined in the real world on a knee mill? It could contour one side, then
you'd need to flip the block over and have it contour the other. But as it
worked it'd be slowly cutting the sides through to the other (To make an
almost fully rounded edge along the sides of the guitar) and I am imagining
the work piece could drop out of the block as it came close to finishing the
edges due to the tool pushing down on it, or atleast it'd deflect somewhere.
My answer to this was to leave something like 1cm uncurved on the edges to
hold the work in place (In the block it's being cut from), then cut the work
out with a saw. I was thinking of making this from something cheap like MDF so
the tool pressure wouldn't be massive on the contouring. I wanted to create an
MDF version then have it cast from magnesium for one seriously mad guitar. A
billet of the right size is a mere 800 Pounds stirling!!! So machining it out
from a billet is _not_ an option. Cast it's more than halved in price. Does
Rhino have a scale option where percentages can be used rather than using the
mouse to scale it? This would be to allow for the 1.3% shrinkage from pattern
to cast. Can any of you guys think of a way that the work could be held once
it's cast and contoured? Having it cast bring up the concern of the neck
binding or something else being just slight too small to fit the neck so it'd
probably need machining after.

Of coarse, just buying a guitar is not good enough, you're on this list, you
know how it is! :)

Sorry it's so long! Can you tell I'm stuck?

Thanks for any help,
John