It does appear that the Eames Lounge Chair & Ottoman you have is the Brazilian rosewood. In 1986 we also offered teak, walnut and a cherry veneer. At the time we offered around 15 leather color choices for the chair. Yours would fit into what we classify as a vintage chair.
For maintenance, we would recommend following the care instructions for 'Oiled Wood & Veneer' in page two of the following care instructions document:
http://www.hermanmiller.com/content...If there is anything else we can help with, please feel free to contact Herman Miller Customer Care at 888.798.0202.