Hi folks!
Is a bit since the last (and first) post of this thread, but I have been quite bussy wth other projects and I could not keep up with this one. So today I decided to go a further with it and here are the results
First I finished the 30 x60 cm part that was missing for the previous post. I had it cut but not glued.
The whole board will look like this

After finishing the frame, it was time to put some paste over the polystyrene, to cover the holes and to give it some uniform view. I used two differnt types, as I had a pot that was near finished and the rest from another which is the one I am using right now for all my projects. The first one will need some 1 or 2 days to dry, but the second one will do it in a few hours. After is completely dry, I will use a sandpaper to smoth the complete set, filling any hole that was left in this previous part.
The board looks like this at this point

So, hope will be able to follow in a few days with this, guys
Cheers!!