Looking at your blowup photo, it looks like the R has been damaged. Photo too out of focus to see anything else but I doubt that there is a DD on only one letter. A DD would have other letters that were also doubled.
A lot of coins do not look normal due to wear and damage. What I see on your dime is just damage. It is only an error if it happens during the striking of the coin. Any anomalies that happen after is damage which is about 99% of the time.
With coins, unless it is a rare coin, condition is paramount. The more a coin is worn or has damage, the less valuable it is. In your case both wheaties are heavily worn so this greatly affects the value.