I am really curious to know what you found out about this bottle. I just found a bottle with the same thing written on the bottom and the same pattern around the base of the neck. The only difference is it is the size of a beer bottle. It says "4/5 pint" around the base. Also I think the first letter could be an A.
I will post a picture when I clean up my bottle, and let you know if I find anything else out. I found it on the property of my 80 year old house.