I don't have a clue, but it would be a good one to me. Odd that it's shaped like a medicine or large flavoring, but the "Full Measure" is something more typically found on whiskeys. "City Agency" would make a very cool name for a package store. Maybe one of our great researchers here on ABnet will give us the real story.
They show up occasionally. For some reason VT whiskey has never been a big interest area. I'd say these days that's probably around $35 bottle, maybe $40. unless their value has gone up since the last one I saw. They're certainly not common. I've always assumed they were similar to the SC Dispensary bottles, only on a single city wide scale. With the few of them I've seen over the years they couldn't have been active for very long. The form puts it probably 1890 to TOC.