Thanks, I go step by step. All the parts could be flattened without intersection (it was not so simple). I quite finished rivets junction, now I want to put caps in order to be able to put a glass on top or bottom. So it will become a low table with 2 positions. I could be done with aluminium. I hope to find someone to paint it before riveting. 

Something like that

@Ivan, I saw you aluminium structure. It is very beautiful. I also intend to use 0.5 mm of aluminium and laser cut.