I came across this great article in the WSJ magazine a few weeks ago. Moscow's Bolshoi Theater, which houses the world's greatest ballerina's, will reopen its door at the end of next month after a $720 million dollar renovation. Since it was first built in 1780, the Bolshoi has been renovated 2 times, making the most recent overhaul its 3rd reincarnation. I love the way they kept the character of the original architecture.
(Above: to restore the luster to the 6 story high balconies, restorers rubbed golf leaf onto 8 layers of clay and egg whites baked for 40 days and rubbed with vodka... only in Russia!)
The original paint and mouldings in the choral hall were a mixture of glue and plaster.
An original plaque hangs in the balcony corridors. During an earlier reno, Soviets replaced the original marble floor with hardwood. This time, restorers found a piece of the original marble mosaic in a well preserved area of the theater and hand-laid the floor throughout to match. They used 11 different marble types!