I have Smithing at 100 with all Perks except Daedric. I also have 4 smithing encantments totaling about 65 points extra Smithing. I can't get Ancient Nord Armor, Ebony, or Branded Iron to Legendary status. Any insight on why I keep failing?

Ancient Nord requires the daedric smithing perk, so those smithing enchantments are likely not enough. Not sure why you're having problems with ebony, unless you're trying to smith an artifact.

The Ancient Nord = Daedric Material is most likely a bug. (Information from CK)
During development someone mistaken Draugr for Daedric.