PORTRAIT BLISS
I got an answer from the National Gallery of Art in Washington, USA concerning the portrait of Ginevra de' Benci. The portrait was restored in 1991 by David Bull. He only got two months to do the job, but since the portrait was in such a good condition overall, it didn't cause any problems. They didn't get to do any scienticif analysis of it, though. They could confirm that it was Leonardo da Vinci who painted the whole thing, except maybe parts of the sky has been painted by a right-handed artist (Leonardo was left-handed).
The continued lacing, which I posted a picture of some time ago, is therefore a part of the original painting, but it had been folded around the wooden frame (as I suspected) and there were deep, visible cracks which kept them from unfolding it until it was restored. It still puzzles me that the lacing don't seem to match up, but it's interesting to see such historical irregularities. Or maybe it wasn't seen as an irregularity at all back then.
They also wrote that the juniper bushes behind her once had been bright green. Leonardo da Vinci used copper resinate to create the green colour, but when that was mixed with oil a chemical reaction makes the colour fade to a deep brown colour. This probably happened within Leonardo's lifetime, so it's not a new element. But it is nice to imagine the portrait with bright blue sky (as it has today), bright green juniper bushes and a waist-lenght figure. Oh, the splendour.
Now, if someone could get their lazy/chicken finger out and spend a year on cleaning the Mona Lisa, I would cry of joy. Yes, I know what's on stake, and I know some people would think that the pale, greyish portrait would be ruined when it actually achieved it's natural colours - but imagine a blue sky, mustard sleeves, a petrol blue dress and a healthy skin colour. THAT would be a masterpiece. I cannot stand to watch the dirty yellow/grey thing they show off today when I keep imagine it in colours. Cudos to the Washington institution that they dared clean the Benci portrait (though, as I've pointed out, I KNOW there's much more on stake for the Mona Lisa).