Making bodywork from scratch

[vojx]

I'm redesigning the bodywork of my Litton, but am unsure of the best/easiest/cheapest method of producing the new shape. At the moment I am cutting bits (as large as possible) of the original GRP and moving them around, temporarily fixing them together then glassing up the insides to stick them together. Seems to work, but I have two worries.
1 - the GRP will be rather thick in places, and so much heavier than needs to be
2 - after a while, will the body start to craze or crack at the joins between panels?
Or should I build the shape I want, make a mould (buck?) of it, then make my bodywork inside of this, with the weight and strength where needed?
But cheaper would be to build the shape I want out of wood, chickenwire, foam etc, then lay the GRP over that, and spend a few months filling smoothing the surface. This should be much cheaper, but would the finish always be too imperfect. A bloke on the Lambo Lounge is doing it this way, but he hasn't posted the reults yet. Perfection is not really necessary since I intend using a matt grey/white/black camouflage paint scheme - that'll hide most flaws!! Could even leave the weave look as a kind of anti-radar reflecting coating.
I question the use of the buck, cos I've done it a couple of times before on small components and the GRP of the lay-up has stuck to the GRP of the buck in places and caused many a problem. I'd hate that to happen to a full bodywork!! And I sure cant afford a professional to do it for me.