I still cant quite tell what you have here, but I can give you some info regarding DDs. If the doubling is flat, and unjoined from the mail letters, then you have what is called shelf doubling (AKA. mechanical or
Machine Doubling). This is fairly common, and often there are tiny scratched metal lines under a letter. This 'error' carries no premium. However, if the doubling is rounded, and sticks up to the level of the main letters, this is an actual DD. Good Luck!