From the Virginia Historical Society you can order a African American Manuscript on a Benjamin Ruff. Although the date doesn't match the Ruff that you are looking for; maybe hes kin.

73. Bedford County, affidavit, 1864.1p

Mss4B3904a1

This April 1864 affidavit of Albon A. Arthur states that

Benjamin Ruff has been taxed as a free negro and has been

treated accordingly.

I have not ordered it yet, I have ordered one on Lott Cary.