Flames of Fair Rhian is in the Endless Paths on level 14, its not hard to find but i think it might depend on how you deal with Maerwald.
Drawn in Spring is on level 12, you get it by helping the Vithrack.
Mabec's Morning Star can be bought from Azzuro when he visit's your keep, so its pretty much random.
Misery's End is a reward from helping Daddy Doemenel in act 2
A lot of the missing ones on the google doc can be bought in Twin Elms.
If anyone has found Purgatory i'd quite like that, a sabre with leech sounds great.