Curious Wing Construction - Fairchild 24, Del Gatto on Outerzone

I started building the Paul Del Gatto Fairchild 24K for a build contest on another site.
This model has an interesting wing. Sheet 3/32 with no span-wise spars. Just semi-ribs to hold the shape of an airfoil as you bend the 3/32 sheet.

http://outerzone.co.uk/plan_details.asp?ID=6152

Thought I came up with a cool way of building by first tacking the semi-ribs onto Dollar Tree Foam Board DTFB.
Getting a curve in the sheet of 3/32 was fairly easy - some heat off a couple of electric burners on my stove, and some H2O via a spritz bottle.

Things worked 50/50 OK. I think I can keep moving forward with what I have.

I used Gorilla Glue brand wood glue on the ribs to top sheet.
I weighed the sheet down on the ribs with bags of rice and popcorn out of my pantry. Kind of made "sandbags" with the stuff and it conforms to the desired shape of the top sheet.

However, after a couple of hours there must have still been a fair amount of moisture in the wood because I lifted the wing, the tack strength outdid the rib to sheet strength on a few of the ribs - they remained stuck to the DTFB.

Also, there was a significant spanwise warp, downward(!) on the wing tips.

Actually, as it perhaps continue to dry it seems to maybe straightening out.

Here's some pics: