sure thing! I use the exact same templates that I do for foam,i use hot glue to connect the pieces using hot glue like most foam builds.
when cutting each template for the cardboard I make sure that if the piece needs to have the right curvature so I align it to the corrugation so that it bends correctly
basically I follow the same process as the foam construction...once I reach the finishing stage, I coat the cardboard with liquid fiberglass resin, I apply about two coats to each side(surface and interior) once hardened I use a rough grit sandpaper to give the resin a slightly rough surface which helps the bondo putty stick to it.
I use anywhere from 2-5 coats of bondo,sanding between each layer,smoothing out any rough or low spots.
its a pretty long,drawn out process but it'll be worth it in the end
let me know if you have any other questions!