> ... nema þeir byrgðu fötum yfir höfuð sér.

> ... unless they covered garments over their heads. (Z.
> draga - d. öndina, to breathe, live)

> ... unless they covered their head(s) with (their)
> garments.

> ... unless they closed over (ie covered) their heads (neut
> plural) with buckets / clothing (dat pl of fata or fat?).

I'd bet on 'clothing'.

> En þeir voru þó miklu skemur inni og fóru óvíðara og
> forvitnuðust færra en þeir mundu ef nokkurum væri inni
> vært.

> When they were yet very brief(ly) inside and went in many
> places and enquiring about less than they would if someone
> would be fit to stay inside.

> But they were still very scarcely inside and went not
> further? and inquired (if it was?) passable, but they
> would if someone were snug inside.

> But they were nevertheless a much shorter time inside and
> went into fewer places (ie in a narrower circumference,
> úvíða, adv) and delved-themselves into fewer (places) than
> they would (have) if (it) were (ie had been) comfortable
> for some (?) inside.

I think that it works better to read <nökkurum> as masc.
singular: 'than they would [have] if [it] were comfortable
for (some)one inside'.

> Eftir það komu þeir út og kváðu þar öngum manni inn kvæmt.

> After that they came out and stated no man free to come
> in.

> After that they came out and declared there (to be) no man
> free inside.

> After that they came out and declared there (ie that
> house) free-to-come inside for no person (man). (Not quite
> sure what this means, perhaps that there is no room inside
> for a person to hide)

Zoëga s.v. <innkoma> actually translates this phrase: 'no
one is allowed to enter'. (A word by word literal rendering
would be 'to no man [is] entrance'.) I'm not entirely sure
what this signifies; the implication may be that in effect
they weren't really allowed to search.

> Mundum vér nú gangast nær ef eigi nytir þú föður míns og
> þess að mér þykir til einskis að taka þig höndum."

> We would now come to close quarters if you don't benefit
> from my father and that to me it seems perfectly clear to
> take you captive. (Z. gangast - g. nær, to come to close
> quarters)

> We will now come to close quarters if you did not have my
> father to thank (z) that this to me seems clear to capture
> you.”

> We would now come to close quarters (see gangast nær, Z16)
> if you were not to benefit from my father (if you were not
> to have my father to thank, 2nd pers sg past subj of njóta
> (?)) and also from that that (it) seems to me (that) to
> capture you (see take e-n hönd,under hönd, Z1) leads
> nowhere (is in vain, to no purpose, til einskis)

Yes: <njóta> is conjugated like <bjóða>, the exemplar of
Zoëga's 3rd Class of strong verb (which is what everyone
else under the sun calls Class 2).

> Hann mælti þá til sinna manna: "Miklu liggur mér þetta
> allt saman í meira rúmi en eigi verði nokkur niður að koma
> mín reiði.

> He spoke then to his men: "This is of great importance to
> me altogether in more space than anyone doesn't happen to
> come down my anger. (???) (Z. rúm - e-m liggr e-t í miklu
> rúmi, it is of great concern, importance to one)

> He spoke to his men then, “It is of great concern to me
> all together, but nothing happened to bring down (reduce?)
> my anger.

> He spoke then to his men: „This lies far more with me all
> together (this is all together of far greater importance
> to me, see rúm, Z1, for similar expression) but someone
> would not need to (verða + inf) bring down (reduce) my
> anger.

The final clause is a bit of a puzzle. For starters, <mín>
(and hence <mín reiði>) is nominative; so far as I can see,
<mín reiði> must be the subject of <verði> (which is a
present subjunctive). In modern spelling <nokkur> can be
masc. or fem. nom. sing. or neut. nom. or acc. plural, but
an older normalization has <nökkur>, not <nökkurr>, so it
can't be masculine. I tentatively make it feminine and
associate it with <mín reiði>. <En> seems to work best as
'and' here: 'and my anger would not would not come down any'
-- I'm thoroughly upset, and I'm not about to cool off.

> Þorgrímur kveðst það nú gera skyldu.

> Thorgrim said for himself now (they) should do that.

> Thorgrim said it now (they) should do (it).

> Þorgrímr declared-of-himself (that he) should (skyldu,
> past infinitive?) now do that.

I think so, yes, and <það> is presumably accusative.

> Var þar engi vörn fyrir því að Andríður var tekinn í
> öndugi sínu og leiddur út.

> (There) was no defense there previously because Andridr
> was taken in his high seat and leads out. (??)

> There were no defenses before because Andrid was taken in
> his high seat and lead out.

> No defence (obstacle?) was there before (them) because (?)
> or for that (reason) that (ie because)(?) Andríðr was
> taken into his high-seat and (was) lead (past part)out.

I like taking <fyrir því at> as a unit, 'because': no
defense was made because he was taken in his high seat,
presumably meaning that he was completely unprepared. (But
it's 'led', not 'lead'.)

Brian