Yes, it is William III (Gvlielmvs Tertivs), and yes, it is underweight - it should be 8.9 - 11.5 g.
The reason for such wide range was a very poor quality control at the mint.
I suppose with all that wear and corrosion (oxidized copper weighs less, doesn't it) could explain the slimming.
The reason for such wide range was a very poor quality control at the mint.
I suppose with all that wear and corrosion (oxidized copper weighs less, doesn't it) could explain the slimming.



















