Some thoughts on locating some of these anchorless houses:

House Braveen in Ep 41 has an estate on Blackmoor bay. Since there is not a whole lot of land between the Glendower and Blackmoor baronies, I suppose the Braveen Barony must cover the "northern downs" and old north watchtower.

The Arthouse dagger was found in Jackport, since Jackport doesn't seem to have any other noble house, I'd suggest listing Jackport as the seat of the Arthous Barony.

Vestfold: According to the FFC Ra-all was promoted to "king of Vestfold", assuming Ra-all was an Andahar, Vestfold could be added to thier seat of power. Vestfold is kind of oddly left out otherwise.

I think this points to a lesser noble house.

Episode 42 takes place at Anathema ;)

Well... the nobleman in Episode 42 seems quite weak and inept... Not sure if Anathema as a stronghold for Hightower family is half-decently strong... perhaps his family has the real stronghold somewhere else and Farlon Hightower is a minor representative of a minor family, or the noble family is not that powerful.