Still grinnin about a day and a half later, so I have to share!
It rang up in the mid 60s on the ATPro and was about 5 inches down...I did the prospector dance! It's dated 1951 from a high school that is no longer in existence and has no names or initials engraved on it. I've done some Google work but have not found any clues as to the possible owner. I shall continue to look!
Here's a vid:
Thanks for looking, HH!