[Nymdok]

Well, heres the quick answer

Size - Diameter - Thickness
Light - 17" - .75"
Small - 24" - 1.5"
Medium - 33" - 1.5"
Large - 42" - 1.5"

I arrived at the answer like this.

Argument By Similarity:
I assumed that all the stats given were for wooden shields of similar tech and material.
Argument By Density:
I assumed that the Weight, implied the volume of material
Argument By Material Properties:
I used the Materials Table (B558) and the Shiled Properties(B287) being careful not to forget that B558 gives data for 10 square feet.

First I decided on a one to one ratio of Weight to Volume. Weight is in the table, so If i figure out thickness, the area will reveal itself through algebra/geometry.

So I started with small shield and made an estimation of X number of inches thickness and Y number of inches diameter.

Using a spreadsheet I fiddled with the number untill I got values that seemed reasonable for all of them with the understanding that technology would contribute to both the DR and the HP of the shield. Examples of technology at work would be layering, binding, iron rimming, lacquering etc.

What it left me with essentially is
Size - MatDR - MatHP - Thickness - Diamter - Area - Volume
Light - 1 - 8 - .75 - 17 - 226 - 170
Small - 2 - 15 - 1.5 - 24 - 452 - 679
Medium - 2 - 20 - 1.5 - 33 - 848 - 1272
Large - 2 - 25 - 1.5 - 42 - 1414 - 2121

Which imples that most of the ability for shields to take a blow is wrapped up in how its built.

Now that we have a basic size, we can do the thickness for the Iron/Bronze shileds. (4e treats Iron and bronze as same)
Metal Shields
Size - Thickness
Light - 1/16"
Small - 1/8"
Medium - 1/8"
Large - 1/8"

Assuming Iron progresses like this
Iron DR HP
1/32" 1 6
1/16" 3 16
1/8" 6 26
3/16" 9 31
1/4" 12 36
1/2" 25 46
1" 50 58


Nymdok
Lord and High Master of Excel Foolishness