That's great you found something. It is really hard to do most times.
I know, stupid Worthpoint-you get all excited, "ooohh, I found it!" and then, "ugh-what the hell....I gotta join?" : )
Duh, I'm an idiot. I have a few bottle pricing books from ages ago sitting near me right now! (Not that it matters too much cause they are so old.) I found what could (probably is) be your bottle (no pics). Entry says, "J. Cosgrove 1866. Charlestown, blue, round 7 3/4" $32-38 but this book is from 1986, so the values are a bit off : ) It's appreciated-yay! Would have loved to have seen the price in say, 2007......