We really don't know enough to give decisive answers. Very few of these sorts of measurements have been taken, so an average can't really be given, and to the best of my knowlege nobody has grided out a piece and neasured it across a grid - an idea which would give you the types of answers you would like.

Best we can do is weights, which give a clue. A full field harness of the era should be weighing in between 45 and 60 lbs or so. If you helmet weighs more than 8 lbs, your full cuirasse more than 25, and your full arm defences more than a few pounds per side, then you are likely using too thick a sheet to make them from.

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armour thickness

And the best part of that discussion was this:

thickness paper

Which summarizes that armour was not made purposefully thicker in some areas and thinner in others. The helmet was 18 gauge, breastplate 16 gauge and was tempered. But this is one harness.

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