Hi, I'm sorry I can't quite remember now but I do remember looking for it for a long time, it was some obscure website.
If I find it again I will re-post.
I did see that on ebay they have second hand assemblies for $30.
04 Boxster RWD Porsche 986 Beige Leather SHIFT KNOB + Silver Button 10,987 | eBay
Thanks
Terry