Greaser errors common, or should I say uncommon?
First welcome to CCF. Second, having some amount of detail missing due to grease in the die is somewhat common. Having lots of detail missing is much less common. While your coin is interesting, I'm not sure that there would be a premium much over face value for it. So, save it if you want, but you haven't won the lottery with this one.
"The danger we all now face is distinguishing between what is authentic and what is performed."