That's someone's monogram, I've seen it before but I don't remember which packing concern used it. If you could decipher the initials, I may be able to find it.
Rob - GlassWorx - Sanford, Maine
hey i have that bottle too, i kept it cause of the monogram,applied lip 3 piece mold?? i dont know what it is either, any help mike , yours looks older , mine is 1890s 1900