Whizz
I.m too late with an idear for body work, but here goes anyway.
Do it the same as you have done BUT use davinicell instead of wood .1/4''
1 layer of glass on the inside set to shape as you have done (glue with body filler)
The foam can be cut to help it bend
You now have a foam surface that can be sanded
Make the tight curved surfaces with block foam and shape to suite
When the shape is good, 1 layer of glass on the outside.
The structure is light and verry stiff.
Look for the red Vincent outfit at BUB and I can show you.
ceers Bones