Wing Root Cover

[Vince Carucci]

The drawings show 1/4 inch plywood blocks glued into the wing roots as screw attachment points for the aluminum cover. I see only 6 blocks and 7 possible holes depicted in the drawing . 

Can anyone tell me how many blocks they used top and bottom? 
Does the 1/4 plywood have enough meat to hold the fasteners? 
What kind of fasteners did you use?

Thanks all.

[kalazzerx]

I was looking at a Kolb Ultralight that has a similar wing gap (was actually looking at how the wing folder but...) and I saw they use velcro and material (vinyl)  to bridge the gap and I am personally going that route instead of using screws and sheet metal.  I want something much simpler to disassemble and reassemble.