Carl Nelson had and may still have some of the original headliner in stock. Purchased a sunroof 2 piece headliner from him a few years ago for about $600 then. Suggest you contact Carl @
http://www.bimmerdoc.com/ about their availability. Believe there were 2 types of headlining materials used by BMW. One had tiny holes/dimples perforated at a diamond pattern and I believe an earlier version that had the exact perforations/dimples with very faint closely spaced intersecting lines over the entire surface area. The headliner I bought from Carl had the former pattern as mentioned above.