Here is a 1909 vdb missing the second 9. I like to think that it's also a grease filled mint mark but I'm doubtful. Am I correct that this is a grease filled die strike? I just realized maybe I should have posted this in the error section.
Grease-filled mint mark, I love how you think, lol. But yeah, that 9, it looks like something plugged it, it doesn’t really look like damage to me.
I don't have an 09 svdb but I have this coin plugged in the hole in my Dansco, pretending to be one. I always wondered about it and didn't know about grease Phil dies until I joined coin talk.