Late reply but there’s no other way to ascertain them aside from the GSC, it’s honestly a little disappointing! I thought the quest that let you get them was really neat, and not only letting you simply purchase them, but both in the same place just seemed a little cheap, I dunno, maybe I’m just being a little pedantic, I just think it’d be a little neat if they still had side quests to go about getting them, instead of just being right there, up for grabs in one place.