Scrooge McDuck's former Money Building
Before the realization of his famous Money Bin, Scrooge McDuck kept his money in this building in Duckburg Downtown. As for Barks reference this is the building of which the floor caved in in the story A Christmas for Shacktown

Don Rosa in his Uncle Scrooge live and times chose for a more linear and easier story narration to ignore this building having Scrooge built the Money Bin on killmotor Hill right after his arrival in 1902.
Anyway it's a matter of fact that Carl Barks in his stories had the Money Bin built only later in 1951 in the story published in WDCS 135.