There is such a lot of information, etc, here, but I'll start with this:
... while the links provided by PDM are from responsible sources and all claim in different ways that whatever work to which they refer is an accurate representation of Leonardo's "The Last Supper" as he originally painted it - the fact remains that none of those sources quote art experts of the reputation and status to substantiate their claims comparable to those provided by this writer in Post #348096 - which clearly document the fact that from what remains of Leonardo's "The Last Supper", no restoration of it can be said to accurately reflect more than ten percent (at best) of what he originally painted.
I know that there has been criticism of the restoration, but, all the same, the restorers must have respect from high quarters to have been allowed to do this work:
Pinin Brambilla Barcilon has conducted this latest restoration of Leonardo's Last Supper under the auspices of Milan's Superintendent for Artistic and Historic Heritage. She is a renowned restoration artist who made use of various new technologies to bring life back into Leonardo's masterpiece. http://www.bringyou.to/apologetics/LeonardoLastSupper.htm
This is what the restorers felt:
Given the radical decay of the masterpiece, the Milan consultants opted for an equally radical solution: to remove centuries of additions, fixatives and repaintings in an attempt to arrive at what was left of Leonardo's original work. The decision would either reveal a dramatically different image than the one that had been seen for centuries or reduce "The Last Supper" to a few isolated streaks of fading color.
"I was certain that there was enough beneath the additional materials to warrant this restoration," says Carlo Bertelli, the former Milan superintendent of art who originally authorized the project in the late 1970's. "Mrs. Brambilla and I had examined the surface with a microscope, and we were surprised to see how much of Leonardo's original work remained. There were also several cleaning trials, with extremely encouraging results." http://query.nytimes.com/gst/fullpage.ht...;pagewanted=all
John after cleaning trials & restoration:http://www.press.uchicago.edu/Images/Chicago/barcilon_john2.gifhttp://www.press.uchicago.edu/Misc/Chicago/504271_john.html
From the book by the restorer Pinin Brambilla Barcilon and Pietro C. Marani
With regard to reliable experts, I have great respect for the Royal Academy, and this is from their site:
To celebrate the Universal Leonardo programme of exhibitions around Europe, September's object is a near-contemporary copy, attributed to Giampietrino, of Leonardo da Vinci's Last Supper. ......
.... Giampietrino's copy ... shows details that seem to have been lost in the original, such as the salt-cellar overturned by the right arm of Judas. Giampietrino is known to have been a close follower of Leonardo in Milan, and, it has even been suggested, may have worked as an assistant on the master's Last Supper.
The Royal Academy bought this copy for six hundred guineas in 1821 ... and in 1825 Henry Fuseli, ... Professor of Painting, was able to deliver his eleventh lecture in front of this magnificent record of the original glory of Leonardo's now-faded masterpiece.
To assure fealty to Leonardo in restoring "The Last Supper" as he painted it, if all these copies referenced by PDM are such close representations of what he originally painted - why not just consult Giampietrino's copy and/or journey to the Tongerlo Abby and/or compare any other copy from the period of these early copies (or later, including restorations) and authorize the commission to restore what Leonardo originally painted to be based upon them?
I'm not an artist, an art historian, or a restorer, but I'd say that it is because they were restoring a specific work ~ not copying another.
Do we know for certain that the early copies were not consulted?
Do you think that the copies, the remains of Leonardo's cleaned original, and the restored version of 'the beloved disciple' are very different from each other?