Is this considered a clad error and does the D, mint mark, look filled in or is it from being so old?
The Mint Mark appears to be filled as far as the coin it appears to be PMD (post mint damage) it looks like it took a hit.JMO Dave
with a D, on the Die that stamps it out is a little pointed piece of metal to form the inside of the D. Since it is "free standing", for a lack of better words, with all the banging against metal, That little piece breaks off, and the result is you get a filled in "D". The correct term is A "Die Chip", or when a small piece of the die breaks off and does something like this to fill in a small area or similar issues.