So, this is how I understand it. By the 1820s there was no demand for a piddly little silver penny and probably little interest in a silver half-groat (2d) either, apart from the traditional annual Maundy giving. Consequently special issues of 1,2,3 and 4ds were minted annually for that purpose. However prior to the 1800s (and contrary to what the RM website says) I can't see that there was any difference between a 'Maundy' penny and a regular currency silver penny. It's just that people have fallen into the habit of calling all small denomination (4d and below) milled silver 'Maundy' money. Or am I wrong and there are distinguising features to, say a 1750 penny that can be used to determine whether it was struck as a currency piece or not?