Garber Facility in Suitland, Md., for conservation and restoration, which has taken 44,000 staff hours so far. Left out in the weather for more than seven years at Andrews Air Force Base, the plane was a filthy, corroded mess of bird droppings and mouse nests when it was finally broken down and trucked to the Smithsonian's Paul E. Although so quickly cobbled together that it has something of the earnest-amateur air of a science fair, the fill-in material effectively exploits the inherent interest of the neat stuff that goes into airplanes and the craftsmanship involved in bringing this aircraft back from near-oblivion. The space that was to have accommodated the controversial original exhibit text has been given over to an account of how the Enola Gay was restored.