Bravo! Thanks very much for sharing! It's very tight for as much as it evokes.

For the sake of demonstration, though, a few nitpicks if you want to strictly follow fornyrdhislag:

1) It's usually, but not always, in 8 line stanzas, and this runs for 10, so not strictly breaking rules, but slightly unusual
2) The first syllable of the second line (B1) is meant to alliterate with one of the stressed syllables of the first line (A1 or A2, or both), and the second syllable of the second line (B2) should not alliterate with the first syllable of the second line (B1), so, unless Kiwis pronounce "Hall" "'All," it wouldn't alliterate with ONE and ALL, and in line 4, FEWS and FOREtold shouldn't alliterate, since they're both in a second line (and FEWS doesn't alliterate with either BREWer or WELcomes).

Here's my attempt to rework with as few changes as I could, to show the rules strictly followed:

1 (A) (A1)ONE-eyed (A2)ALL father
2 (B) In (B1)ASgard of the (B2)SLAIN,
3 (A) (A1)BREWer of (A2)WELcomes
4 (B) The (B1)WYRDS have (B2)FOREtold,
5 (A) May (A1)MUNinn ever (A2)HOLD to
6 (B) What (B1)HUGinn in(B2)SPIREs,
7 (A) So (A1)REACH deep into the (A2)WELL
8 (B) As the (B1)RAVens (B2)CAW,
9 (A) So I (A1)WORK the (A2)RUNES
10 (B) My (B1)WYRD to (B2)KEN.

But again, I like what you posted and I'm just sharing this for anyone following along at home, and as you saw in this post, I'm not above breaking the rules for poetic effect!

Cheers,
Jeff