Interesting, Woody!
Not that this has any direct relevance to your specimen, but I have a recent acquisition which caused some similar head-scratching:
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Looking at it, it really appears to be a crown top applied upside down, but I've heard from a reputable source that this bottle has a patented lip design and stopper, and in all probability, yours does as well.. and although I hope you find out something about it, I'd consider it a good thing if nobody knows! []
On Todd's web site, Soda & Beer Bottles of North America, the bottle is listed as having a inverted taper with a combination bottle closure and being circulated from 1864-1866.
Chris