I know there are many famous valyrian sword in the mod. The Redwyne lord of the Arbor has the Redwyne. Stannis has the Lightbringer. Jon Snow has the Longclaw. You can capture them and kill them for those sword. I see that the Ice and the Dawn are also in the mod. I thought either Tywin or Joffrey has the Ice because the Widow's Wail and the Oathkeeper haven't appeared yet but turns out neither of them has it. Anyone knows how to get the Ice? I also have no idea whereabout the Dawn too since it was lost after Arthur Dayne 's death in the books.
In regards to Dawn, it was not lost in the books after Arthur Dayne's death. Ned Stark returned it to Starfall (the seat of House Dayne) as a sign of respect.
As for Ice, I wouldn't know other than using cheat menu and the "find an item" option.