Dug out the Revell Viking Longship at last and began the basics on the model. It looks good and the scale (1:50) seems to work fine with 28mm. Clearly it needs a good paint job and some modifications - not too sure about the plastic sail. Some folk have also worked this as a waterline model and it looks great but I am not sure if I am brave enough to do this as I have been a long time out of modelling! Check out Herrodadog's Viking Longship & Kevin Barrett's Longships among others for some nice examples of how the ship can look.
As far as being an accurate model I found a helpful quote by 'J Tilley' from Model Ship World -
"The Viking ship kit was based on a full-sized replica that stood at the time in Lincoln Park, Chicago. That replica was, in turn, based on the Gokstad Ship, one of the two major Viking ship "finds" now preserved at the Viking Ship Museum in Oslo. The Revell kit is a quite accurate reproduction of the Gokstad Ship - with a few parts simplified (e.g., the insides of the gunwales, where the straps on the shields are supposed to be hooked) and a few others based on speculation and inference. The most obvious in the latter category are the "dragon's head and tail" at the bow and stern. The actual Gokstad Ship was buried in a funeral mound, and the bow and sternpost projected into a higher, more acidic layer of soil. When the archaeologists excavated the ship in the late nineteenth century whatever ornaments had originally decorated the bow and stern had rotted away. The ones on the Revell kit are reconstructions based on other Viking artifacts of about the same period."
A few pics of the model...
Basic hull of Longship constructed (with Bolli onboard getting rather excited at the prospect of going 'viking')
The motley crew and longship apparently stranded on a garden chair.