Please let us know where you are located. Someone might know a local source. Until then checkout the catalogs at
http://andersonmcquaid.com/anderson_...downloads.html. If you don't find it in their catalogs, it probably doesn't exist. They are in the Boston area. If you're not in the Boston area print out the page and take it to your local shop. Most of the molding cross sections print at close to actual size.
I have used them for over 30 years and they also supply that fancy PBS show. I loved digging through their scrap heap. My favorite find was paying $1/ft for exotic molding originally designed for the executive floors of a Boston high rise. The client paid $20/ft for it 30 years ago.