I visited the house as the Museum of the History of St. Petersburg and except for the two staircases (the main one and the wooden one that lead to the upper floors) I can't recognize any of the rooms. But I remember most vividly an attendant who must have been in her seventies or even eighties, explaining to me in Russian about the Rumyanstev's. I couldn't understand anything but "Rumyanstev" but she made me understand that she was proud of the family and their contributions to Russia.
BobG
Well, it's really interesting that the mansion is called now
the Rumyantsev not the Leuchtenbergs (who had lived there before the Kochubeys), or the Kochubey. Count Nikolay Petrovich Rumyantsev (1754-1826) bought the mansion only in 1802 (the building had belonged to the Golitsyns) - he was the Chancellor of the Russian empire ans a patron of arts and sciences, and he collected artifacts of Russian history and culture and wanted his house to be The Museum after his death. And the mansion was the Museum in 1831-1838 years though it was moved to Moscow in 1861. In 1882 the building was purchased by Zenaida Beaugarnais, wife of Duke Evgeniy of Leuchtenberg.
So now that's the Rumyantsev mansion in honour of the famous owners and collectors of the XIX century.