You were well informed........... when told it is very rare!!!!!
The lead solder in the back looks to be a bit unstable and prone to crumble. Please handle this with care! There are professional relic restoration experts, that could do an excellent job of repairing the small face crack, and stabilizing the back. This is a valuable relic, so care for it well.
Nice Find. Marylands Eastern shore has some very good history. I know I detect it all the time live here. Right before the 4 of July last year I dug a 1793 Chain cent from the shore. Grats on a Banner find and if you ever want to hook up and detect let me know. I go all the time. You find any reale's or old silver from the farm yet? I'm sure there are some there.