Mies van der Roheís S.R. Crown Hall, modernist architectural masterpiece, hasnít looked this good since the day it went up 49 years ago. The structural steel is freshly painted in "Mies Black." Thereís brand-new glass, a restored south entrance and much better ventilation. The $3.6-million restoration began with repairs to building wiring, upper-level woodwork, rest rooms and the south entrance. Over this past summer, the steel and glass were done. Yet to come are improvements to landscaping, fire safety, and energy efficiency.