Company Names, addresses, dates¹:
  Alex Guinsburgh (Saloon), 2500 G Street NW, Washington DC (1902)
  Alex Guinsburgh (Grocery Store), 1645 19th Street NW, Washington DC (1903-1908)
  Alex Guinsburgh (Liquor Store), 1523 11th Street NW, Washington DC (1909-1910)

Notes:
Alexander Guinsburgh was born about 1873 in Russia. He came to America in 1892 and was naturalized in 1897².
The city directories list Alexander Guinsburgh under Saloons (1902), Grocery Stores (1903-8), and Liquor Stores (1909-10). The 1902 Saloon entry matches the address on the bottle shown below, which refers to his establishment as a "buffet".
An article in the 13-Mar-1910 issue of the Washington Post says that Alex Guinsburgh applied to change his name to "Alexander Leonard Gill", because his name was often mispronounced and mispelled, and it led to confusion with the delivery of his mail.
After changing his name, Alexander Gill doesn't seem to be listed in any bottle related businesses. He was listed as working for the Washington Gas & Light Company in 1916.

Bottles:

book # 287 Aqua 9.5" blob-top bottle embossed: round slug plate: ALEX GUINSBURGH'S / BUFFET / REGISTERED / 25TH & G STS. N.W. / WASHINGTON D.C. above slug plate: REGISTERED below slug plate: THIS BOTTLE / NOT TO BE SOLD