Good Job so far. I have a couple of questions and comments. You did not mention what that filler you were using was, but it looks like some stuff I have used. It comes from the home improvements store. The stuff I get locally is called Patch'n Paint Lightweight Spackle. I am sure it goes by a different name where you are. I swear, the first time I picked this stuff up from the shelf in the store, I had to open the tub to see if anything was in it. It is probably less than an half pound/cubic foot. Is this the same stuff you are using?

Also, the technique I use when gluing with CA in this situation is to first spray one surface with accelerator, then put CA on the other surface then stick them together. In this case, I would have sprayed the foam, then put a thin film of thick CA on the wood. Usually I would make a few practice runs placing the wood before actually gluing. Where I have done this has not been in this exact situation. I use it, for example, on sheeting built up wings. I spray the sheet with accelerator, then run a bead of thick CA along the tops of the ribs, and spar. I use pins stuck into the spar as "stops" to place the sheet against, then use a long aluminum angle to "roll" the sheet toward the L.E.

I don't think this would work (or even be desirable) for sheeting an entire foam wing. It should work for a patch job like this though.