Thanks guys. My thoughts so far:
Drag reduction, no open gaps between any flying surfaces and a very smooth and shiny epoxy resin impregnated faux silk skin to replace the coarse Dacron finish.
Better lift, new foam ribs with lower shape to replace the top only alli ribs. The skin can adhere to convex or concave shape so profile change is possible. Leading edge will be internally supported to eliminate scallops.
Kasper, the plane was originally grounded due to perished Dacron so no need to sew anything. I believe my plan will work out a hell of a lot cheaper than new skins($2-3K)
My wings will also be of the folding type so that towing and rigging is a one man operation.
So back to the original question, a new profile without changing the width (spar to spar)? Would a slightly convex bottom be of help?
BTW, it's 10- category.