Really nice example but is there a way to get all that gunk off?if not then possibly best to put it back in the roll.
I'm not seeing doubling. It looks like a hit. That gunk is zinc bleed. Even if you could get it off, it will continue its path to self destruction.
This is a tough one to pick up on after scanning thousands of cents for the year. It always appeared to me that the ear was fuller and rounder than other years with the same ODV. Or maybe my eyes are crossed.
Look for a plastic bottle, like one for medicine , put white vinegar in the bottle, maybe just a little bit more than the coin's height will be....Put your coin in the bottle and try to get the top of the coin against the side of the bottle and the bottom of the coin away from the side of the bottle a little bit so the vinegar will get behind it and end up being on both sides of the coin......Now put some baking soda into the bottle but just a little at a time because once the backing soda hits the white vinegar it will start bubbling...a lot...sometimes if too much baking soda it will bubble right out of the bottle till it calms down....After the bubbling stops you will see small bubbles on your coin....This is what's cleaning it....Keep an eye on it once in a while cause you will have to put more backing soda in the bottle.....It took me a while to get used to this, but I will tell you it does work like 90 % of the time...Good Luck!!