We did some stuff that you may like. For exemple the dentist http://www.calimacil.com/nails-staff.html. We work on a hammer. We will have to think about some other weapons you suggest.
We are working on it. we search for the best composition : foam and core. We do not forget this idea, we will find something to work it out! But that’s a big challenge.Ladamannen commented
Well if you do actually decide to make viking shields (I would love that by the way) Please try to make them size accurate as they should have about a 3ft radius, I realize that this might become a little heavy but if you make it with light materials and maybe have less foam around the "middle" parts of the shield and mainly focus on the boss and edges it could very well be wieldable.