It’s wonderful news, but what if it isn’t what the artist wanted?

According to a short piece in the “Antiques” column of the October 14, 2011 issue of The New York Times, the anaylsis and treatment of Alfaro Siqueiros’ mural, “American Tropical” is nearing completion and an interpretive center for the mural will open next fall. Due to its controversial political subject matter, the people who commissioned the mural had it painted over immediately after it was completed.
Siqueiros had said that his mural should never be restored as the evidence of censorship was part of its history. How should/do conservators proceed in situations in which the work they are hired to do is in contradiction to the desires of the artist?