I've done a number of historic feasts, including Roman and Elizabethan for a local university.
I concur, what we know of Vikiing cuisine is not appealing. But, some general medieval dishes might do the trick, as there was a great deal of cross-cultural contact between the Norse and other peoples, and I imagine they ate much better than we think, and had access to a great many trade goods, and slaves who knew how to cook must have been put to work on some farms.
I can give you a list of historic cookbooks available in print, or send you some recipes, as well, just let me know.
Dane