how do I do this?

 From:  Colin
1977.5 In reply to 1977.1 
Hi Rudy,

Here's a basic version I did based on your supplied curves.
It still needs to be shelled or hollowed out.

I ended up splitting your crescent moon shape & using them as a 2 Rail Sweep.
I also tidied up some of the points in those curve towards the very ends.

Hope it helps, Colin

Edit: I just quickly did a hollowed version.

EDITED: 17 Sep 2008 by COLIN