However it is believed to be late 1800’s there are some bubbles in the glass 

Not at all familiar with the actual workings of the burner so I cannot comment on condition Queen Anne with portion of original wick. 

I will try to answer your questions. 

Approximately 6 inches in diameter .. some of the photos show the purple “ HAZE” coloring in the glass

Please take note of the rare shape of the finger handle