very nice button man. Eagle D overcoats are not as common as folks like to believe. I dug two last year at a CS site along with CS buttons and those were the first two I had dug in over 10 years.
That is an awesome find. That is 1 of those definitely still on my wish list. I would love to see a picture of the back. Or even just post what the back mark says.
Nice late-Dragoon era button. Missed your posts. Will PM you as I said I would with some research info that may help you. Haven't been able to get to it yet, but did not forget.