Welcome to the forum.
The S.O. Dunbar's with a pour spout are generally considered to be master inks. The pannel sided ones made for them are also inks. The cylinders like yours without the pour spout are normally clasified as a medicine.
Nice find. Looks like it'll clean up real nice.
There is another american burst top ink made here. It looks like a house and is embossed NE/PLUS/ULTRA on the roof. I was told this was blown in a western glass house.
There is one that is believed to be made in England, if it is it's scarce/rare . There is at least 1 made in the states that I know of and it's embossed on the base KIRTLANDS INK. Kirtlands ink was from Poland, Ohio.
Welcome to the forum. I am sorry to break the news to you but the "Jenny Lind, Fisherville" bottle is a fairly modern reproduction. The Franklin/TWD bottle held Lestoil and is from the 1950's /early 60's. Pretty to put in the window, but not worth very much.
They were normally filled with carbon tetrachloride a very dangerous chemical to your health and the environment. It was used against fires by depleating oxygen at the source at the flame. It was very effective against electrical fires like halon was.
What color are they?