In a few weeks the Guggenheim Museum will open a show of Malevich paintings with important works that have never been seen in the West. But the tale of how the paintings ended up getting out of Russia and into the show is a tangled one. “The art dealers, the Guggenheim and Russian officials all deny having done anything improper. It is through their efforts, they argue, that superb art hidden for decades is finally being seen.” But still, there are questions…