Weak Letters Faded Into Coin Or Missing

This very common. It is not from die wear, but from the die being filled with a substance like grease. When the coin is struck with this blockage, the devices can't form because the cavity of the die is filled in with this substance. Happens a lot. Sometimes harder to find one that this doesn't happen to. It happens. Dies are negatives of the coins they create. The devices are deep into the die and the fields are the outside edge of the coin. Thus scratches on the field that flow through a device can be seen on a coin and you wonder how did that happen without disturbing the device. It is on just the field, the outside of the die. Cleanings, polishings and abuse usually affect the fields and not the devices deep into the die.