Hi Blair,
I'm using the WID data. If you're searching for div./int./C.gains you'll need to look for data constructed with the previous methodology (pre-DINA, based on households). It's still there, but takes some effort digging through the categories. If you want a shortcut, you might find it in Saez's site. Download the excel file from:
"Income Inequality in the United States, 1913-1998" with Thomas Piketty, Quarterly Journal of Economics, 118(1), 2003, 1-39 (Longer updated version published in A.B. Atkinson and T. Piketty eds., Oxford University Press, 2007) (Tables and Figures Updated to 2015 in Excel format, June 2016)
The top 1% income composition is there, though only presented with the first and second methods I spoke of above.
Btw, S-corporations income won't be registered there as dividends, but as part of entrepreneurial income (in DINA, it will register under "capital component of mixed income" if I recall correctly).