Cat only shows the assembly on their parts schematic ($80!) but I don't see any reason you cant get just the needle. Take the number off the carb and do a little internet searching. Mikuni probably uses that needle on several models.
Just posting to end all the discussion.
Ended up putting in new top end because of low compression, new float in the carb.
Sled is now up & running strong. Thanks for all the help.