Twain Web members--
I've posted some recent photos of Villa di Quarto, the Clemenses' last residence in Florence (1903-04) to photobucket.  This is where Olivia died.  The link is below:
http://s896.photobucket.com/albums/ac167/freihowe/
You might want to compare these with images that were included in a contemporaneous piece in _The Critic_   Barb's www.twainquotes.com site includes those here:
http://www.twainquotes.com/interviews/critic1904.html
I believe Kevin MacDonnell has some photos that Jean took of the residence and grounds during this period.  Perhaps he'll describe those. 
The building has been divided up into as many as 20 or so apartments.  As I mention in the brief description, I was unable to gain access into the main villa, so I cannot comment on the interior.  Similar villas of this size have enormous rooms with 16-20' ceilings.  And usually an even grander central reception hall.  
Jacopo, my host, rents space in the carriage house for his business, and he showed me part of that renovated space and guided me around the exterior of the villa and the park.  
I'll post some images of Villa Viviani, the Clemens 1892-93 residence in Settignano, also overlooking Florence, but a little to the south of Villa di Quarto.  
Hope you enjoy them. 
Best, 
--Larry Howe