Beautiful find indeed, and always welcome. I have found 2...the first in '79 about 4 inches away from a chain-link fence. Was using a White's 6dB at the time in TR disc. mode. I had "tuned" the unit to the fence and walked slowly down its length...something you could do with the non-motion TR circuitry. Got a good solid
signal and there it was. As with yours, it was dateless ( date wear being a common failing to this coin design). Still a thrill for me though. Found my second one
3-4 years later in school yard from the 50's (again, no date). From a numismatic standpoint, this coin is one of my 2 favorite designs along with the Walker half.
In mint state they are truly beautiful. You should definitely re-hunt the site.....might be another one there! Great job.