> en þú hafðir ekki
> but you had nothing (in return?).

MM & HP: "and you could do nothing about it." But I would have
translated it as you did. Is this an idiomatic way of saying that he
couldn't do anything about it, or have MM & HP just made a paraphrase
based on what "but you had nothing" implies?

> Kunna þótti eg norður þar
> I am thought to know (something about it) in-(the)-north there

Literally past tense, "was thought to to know." MM & HP: "They used
to think so [that I knew something about law] in the north."

> lögheimili

MM & HP: "legal residence." How exactly this was defined in Icelandic
law at the time, I'm not sure.

> handseldri sök

See my comment for Grace [
http://tech.groups.yahoo.com/group/norse_course/message/7126 ].