1976 Bicentennial RPM? Also 1982-D SD RPM?

Your 82 is a large date. You will need to post much better photos for us to help you properly. The better the photos you post the better we can help you. What is your photo taking set up,camera-lighting-etc?
John1

Just field distortion with die flow. (worn die wrinkles to a senior die) On the mintmark, there is just a normal design on that area. Keep in mind that during its life, it has been in many vending machines altering the coins each time they are used. Not the right side of the mintmark. That is the circulation flattening I'm talking about.
Just one listing that year from that mint:
http://www.varietyvista.com/09b%20W...6DRPM001.htm
You can see the center post has been broken off of the die, thus making the mintmark look like it is filling.

When I mention post damage it can go in states:

How can it be progressive? Well consider this:
The post is on the die decending downwards. As parts of the post break off, the post gets shorter. Thus the bottom can break off first leaving less deeper center on the device. As it continues to break off, the mintmark on the die becomes a larger void on the die. When this happens then the post goes away more and more. But then the base of the post breaks off lower into the die, the void can become taller than the mintmark itself.

Thus the base where it broke off on the die, will show above the top of the mintmark. That is what you are seeing the two images on the last set. (This point came to me a few months back, and the explanation is now being posted) Where else do you get up dates on new information discovered? Just here.