I am going to guess that it is vintage or was owned by the client and has been re-upholstered. It's pretty easy to find this type of furniture either on craigs list or at estate sales and just have it re-covered with a great new fabric, sometimes you don't even need to refinish the wood. Some vendors are making versions of this style of furniture, meant to look old and found.

Here are some examples of new options in a similar style:

http://www.noirfurniturela.com/SOF172WW.html

http://www.noirfurniturela.com/GCHA151-3WEA.html

http://www.anthropologie.com/anthro/catalog/productdetail.jsp?id=063271&catId=HOME-FURNITURE&pushId=HOME-FURNITURE&popId=HOME&navCount=72&color=095&isProduct=true&fromCategoryPage=true&isSubcategory=true&subCategoryId=HOME-FURNITURE-LIVING

http://www.anthropologie.com/anthro/catalog/productdetail.jsp?id=960076&catId=HOME-FURNITURE&pushId=HOME-FURNITURE&popId=HOME&navCount=72&color=049&isProduct=true&fromCategoryPage=true&isSubcategory=true&subCategoryId=HOME-FURNITURE-LIVING

Good Luck!