IIRC they were 39 teeth in stock form and made of steel. You can get a full range of alloy units from either AFAM or Sprocket Specialists.
All the modern Ducs, short of the SSS Monsters and Superbikes use the same bolt pattern for sprockets. I change sprockets between my 02 800, 851, 888 and M900 frequently. Depending on my mood and where I am riding
