Grease filled die- an interesting, but common error. I hope you didn't pay much for it. Value: ≈$4/$5
I wouldn't pay more than F/V for it honestly. It's cool, and I would keep it if I found it...but that's as far as it goes. Here is one I found that is missing way more detail than yours and I paid a whopping .01c Welcome to CT and I wish you luck selling your coin.
Very common. Nice to have a greaser but I can find them in circulation if I've a mind to search for them.
The reverse has Zinc-Rot and plating splits. I would not trade you a cent for it. But this only my opinion.