Russ, the Sutton Hoo shield with which I am familiar is a pretty much standard circular shield as used by the Teutonic tribes, if rather more elaborated for a king. If memory serves, it was about 3' in diameter with metal edging, a central hand gripcovered by an iron boss of Anglo-Saxon form, and had metal strengtheners on the front in zoomorphic form. As is usual, the habd grip extends across the back of the shield to make a rigid support to hold the planks together, as it was made of several planks laid side by side. All in all, not too dissimilar from the later Viking shields, as found with the Gokstad ship burial of 200 years or so later.
The celtic shield of which I am speaking is of a much earlier period. Sutton Hoo dates from ca. 700 CE, while the shields to which I am referring would date to the period of the Roman Conquest and before, a period that was pretty much ended by, say, 200 CE at the latest. Claudius was the Emperor who pulled the trigger on the invasion in the 40s CE, although we all know that Caivs Ivlivs Caesar had done two rather intensive scouting expeditions in the 40s BCE. before he became occupied with the Civil Wars, Pompey, and Cleopatra. These oval celtic shields were large body shields of the sort that one might expecct to have been used by warriors who went into battle wearing a torc and naught else. And they were the specific target of the Roman pilum, the heavy javelin that the Legions used. A volley of pila had the effect of spitting as many of the charging Celts as possible, but those that didn't hit flesh would almost certainly hit the shields, at which point the soft iron shaft would bend and/or one of the two rivets holding the shaft to the wooden part of the assembly would shear, resulting in a 7' encumbrance to the shield. The Celt, anxious to get to the enemy would throw down his shield, and you can pretty much forsee the results of the coming clash with an armed and armored Legionary moving forward in his ranks, using his gladius.
