You're aware of this link, right?
http://www.speakeasy.org/~sven/site/radius.html
Never done a Sabre shape myself.....but do know some builders on this site have attempted it with some very nice results.
Look here:
http://projectguitar.ibforums.com/index.ph...ic=26137&hl
Maybe you should PM him and get some pointers. Didn't seem like awful complicated build. The thing that throws me is not the curve on the body but the input jack. Would not know how I could pull that one off.
That's route I would take, make a template...and practice curving body on cheaper piece of body wood, but not through industrial copy-carving route, but involving more elbow grease and simple sanding disks/blocks/scrapers/etc. Sometimes these things look sooo complicated but once you start with them they seem rather do-able. With S body in the house, you should get decent measurements, and should come close.