Several decades ago - 4 or 5 at least - I saw a plan in a model aircraft magazine for a very simple rubber-band driven plane that used a piece of a dry cleaner bag (thin plastic wrap style) as a Rogallo wing. Wingspan was maybe 2 feet. Wing spars were simple 3/16" (approx balsa sticks), the body was simple balsa too. Flew great - I built several back then!
Now, I'd like to experiment with that again and would really like to have some tips - the original plans would be great if someone has a stash or online scan of it in whichever model aircraft magazine it was ... but any information on model-scale Rogallo wings would be useful to get me started.