As to rust, red haired peoples, freckles and relationships (disfunctional or otherwise):

"In 999, the Viking king of Dublin, Sitric Silkenbeard, surrendered to Brian Boru. In 1014, High King Brian Boru of Munster defeated the allied army of the Vikings and the King of Leinster at Clontarf. Thus ends Ireland's Viking Era".

The Viking era ended in Ireland - (or did it?) No treaties were signed. But, the Viking "red" pumps in Irish veins. Viking "rust" never sleeps, in Ireland, or where the Irish roam.