Sorry I didn't have any of that information when I posted it. I believe I have solved the mystery.
Based on the size of the lines on the crown and the location on the few letters that are legible at the top of the coin, I think it is a 1821-1840 4 Pfenninge, Friedrich Wilhelm III.
Thanks for looking and the private messages from other hunters!
If you think it could be something else, please let me know.