The M stands for Mason O Fuller. The Brooklyn City Directory’s for 1862 and 1863 listed him under Soda Water located at 75 Remson. The Brooklyn City Directory’s for 1865 and 1866 listed him under Soda Water Manufacturer located at 67 Remson. Strangely he was not listed in the 1864 Directory.
We know he was in business in 1861 (the year is embossed on the bottle) but he’s not listed in the 1858 Directory, so the business started sometime around 1859/1860. He was not listed in the 1867 or 1868 Directory’s so 1866 is possibly the end date.
Today both 67 and 75 Remson are old brownstones with a cellar under the main entrance stoop. They are probably the same buildings utilized by this business.
The bottle is a pony with an applied blob finish.