> Gunnar reiddist og kvað þá bætta fullum bótum er eigi væru vaskari

menn er Atli var.

Patricia: Gunnar became (was made) angry and declared that full
payment had been made for lesser men than Atli.

Grace: Gunnar became angry and declared then compensation fully paid
when not were more valliant men than Atli was.

If I've understood this correctly, 'þá...er' is relative, "those
(masculine accusative plural)...who". The victim whose death is being
compensated for is accusative, the payment dative (in its instrumental
role as the "means by which"). 'bætta' is masculine accusative
plural, of the past participle of bæta (=boeta), to agree with 'þá'.
So, lit. "Gunnar became angry and declared those compensated with full
compensation who were not braver (i.e. better) men than Atli was."
Patricia's translation looks to me like a good paraphrase.

Hmm, I've just noticed that says 'er' rather than 'en'. Is that a
mistake?