I was thinking about what you do and also was thinking about the so called ""Carbon Wing by Windy. I came up with ""The poor mans composite wing/ Fuselage".
This is the method to my madness. Generally the whole construction is 4 ribs on two rods and then you apply molded skins on top of these 4 ribs.
Molds
Cut the top view out of two pieces of MDF. Little extra for the TE 3/8 is plenty and the rest is to size. Make ½ Plywood ribs (root tip) or more if you want elliptic shape and glue in position on top of MDF. Fill with foam in between. Hot wire or block sand to finish shape. 3M77 a sheet of polybag on top of mold. With this the mold is done.
To make the skins use fiberglass 3/4oz/yd2 and 1/20 balsa then fiberglass again. Make sure there is NO dust on balsa, blow with compressed air or wherever you need to remove the very last speck of dust.
With 3M77 make a fog above the balsa sheet and allow it to fall on the balsa sheet. Lay the balsa over the fiberglass (fiberglass bias 45 degrees). Repeat to put the fiberglass on the other side.
Use a foam roller to apply the resin and apply it dry (you have to push a little to get things wet).
Put the skin over the mold and vacuum overnight.
Use a Exacto knifeblade glued to top of a piece of scrap MDF and walk around the LE to trim to size.
Get the 4 ribs on the two rods add a TE to the back of the skins. Mark the LE center line and place the skin trimmed LE on top start gluing and work your way from the LE towards the TE. Repeat for the top.
Obviously the same can be done for a fuselage or a stab.