Grisaille Layer with mistakes scraped out

Three weeks ago I did the Grisaille layer. This increases the fat of the paint, as there's 1 part Stand Oil to 5 parts of Turpentine. To the Raw Sienna and Burnt Umber, I've added Titanium White to the palette.
The objective here is to finalize the details - which in this painting mainly consist in adjusting and correcting the shadows - and achieve an overall effect of a moonlit monochrome picture.
I believe this effect was achieved, but there was something so wrong about the whole figure and I couldn't figure out what it was.
I let it to dry, as a couple of weeks are needed to pass the simply dry-to-the-touch stage to a good dryness of the film of paint.
In the meantime I kept looking at it, and comparing it with the drawing.
Finally it dawned on me that the wrong thing about it was that the left part of the figure was way too narrow, compared to the right part.
It wasn't that visible from the figure itself (at least to mine not-well-trained eyes) but became rather apparent when looking at the margins: the left margin, even accounting for the halo, was way too wide compared to the right margin.
Given, however, that I took great care to align the neck, the spine and the line between the cheeks to the exact middle of the picture (had a string-hook pasted at the back to allow for hanging and drying safely out of ZeeBee's reach), this difference in margins shouldn't have been there.
So I took some tracing paper and placed it over it, drawing the middle line first, and then tracing all the right contour.
At that stage, I cut out the paper following the contour, and simply reversed it, placing it therefore on the left side.
The difference between the two parts was enormous.
I traced directly on the painting with a pencil the correct contour, and then I scraped very delicately with the spatula all the film of paint that was between the newly drawn line and the edge of the painted figure.
It wasn't that easy, as I didn't want to loose the gesso layer of the background. Unfortunately the Underpainting Layer got lost as well, but at least I kept the white gesso ground.
So here it is the Grisaille layer with the scraped contours.