Congrats on a really nice find. I had never even heard of a Hardee hat pin before so I googled it. From the few I looked at it seemed the upper part from the top of the wings to the head were more filled in with background. Any hallmarks on the back?
We have some very sharp and knowledgeable folks on here that go into Civil War relic hunting and after a day of your posting I would have thought more would have chimed in by now.
If you look at this one you will see the fouled anchor it has the entire anchor and mine is missing the lower half. I suspect mine may be an earlier issue.