Heill aptr, Pætr.

> below you typed
>
> Haukr Skáneyjarjarl
>
> Is jarjarl correct or a mis-type ?

:) So you don't like Jar-Jar?

This is quite correct as it is.
The 'ey' in Skáney is the normal
noun for "island" and its genitive
form 'eyjar' is beyond doubt. The
genitive of 'Skáney' is even specifically
attested more than once in old poetry.

Hafði för til ferju
fróðr Skáneyjar góða
blakkríðandi bakka
barnungr þaðan farma.

- Glúmr Geirason

Selund náði þá síðan
sóknheggr und sik leggja
vals ok Vinða frelsi
víð Skáneyjar síðu.

- Goðþormr sindri

The genitive is, by the way, what corresponds
to the English 'of' (as in your original question).

Kveðja,
Haukur

P.S. There's more than one version of the Landnámabók
extant but in the one I checked the name Guðrøðr doesn't
occur in the nominative at all, so you'd be hard pressed
to use that as evidence for its r-lessness.

P.P.S. Since we're mentioning "island" I'm told that
its first component is really not French/Latin as
one might think. The word should be compared with
Old Norse ey-land.