Re fargo.. Yes, I know about Hjemkomst, but I haven't seen it for myself (yet). As far as I know, it is a full scale replica of the Gokstad ship. 24 metres long and very seaworthy!

This is an interesting channel! Have you ever seen the Hjemkomst Viking Ship in Moorhead, MN? Apparently it is based off the Gokstad.

Just go on and explore, deiktes. It's really fascinating!

I had a look and I think that I found what you are talking about, believe me, I had no idea about it, and I think it is extremely interesting

Another possibility is the Greek myth of Apollo's trip to the land of the Hyperboreans, possibly in the areas were the ancestors of the Vikings lived, for when you remove all the "fairy-tale" elements from this myth, it is a story of two developed civilizations, one to the far North and one to the South, who were in touch for a long period, that also explain many of the similarities you mention, plus indicates an exchange of myths and legends, and influences to each others culture.

On the other hand, since both people lived around the sea and from the sea, and travelled on the sea often, it isnt so strange to end up with similar ships, they had the same demands from them after all! But this would leave the"Kivik grave unexplained.
So I must accept that the "almost nothing» I used was not correct, what I had in mind was only the recent history, maybe because we tend to put the Vikings in a very tight chronologically period of a few centuries, something that of course leads to mistakes.