Streamline floor/shell construction

I saw a past post with this same question, but can't find that post now. Either way, nobody responded to the post, so here it is again!

Does anyone know how the plywood floor interfaces with the shell on a 1969-1974 Streamline? Is it like an Airstream, where the plywood was laid on the frame and then the shell on top of the plywood? Or, I have heard Argosy/Avion's were constructed differently?

I'm acquiring a trailer of this vintage, and mentally prepping for what's to come.

Thanks!!