I have been in correspondence with the curator of arms and armour in the Royal Armoury Collection, Stockholm regarding the crossbow (below) and he has very kindly taken photos, measurements and provided some notes which I have permission to share with you, hope you will find them interesting.
Before I start, I believe this is the bow posted to Viking Sword, examined by Mikael Dahlström who sometimes posts here, and which he identified as a wood-and-sinew bow. I would love for Mikael to join in on this one.
The museum catalogue, however, describes the bow as made of two layers of wood (presumably yew) and horn. On inspecting the crossbow, the curator did agree that the bow does look like it is made of yew and that it is hard to see if there are any horn at all, stating the front of the bow looks like it is horn as suggested in the catalogue online but that the material is hard to identify since it is partly covered.
The whole crossbow weighs 2000 g. The thickness where the bow meets the stock is 45 mm. At the tip of the bow it is approximately 26 mm. From tip to tip it is 700 mm long, and front to end the stock is 710 mm. The height of the stock is 65 mm where it meets the bow.
The bow is partially covered in printed birch bark and the front would have been striped in black, white and natural wood colour.
Enjoy the pictures, any and all comments welcome.