I can only find two references for Schwartz’s Dairy at the Woodhaven Queens location.
Schwartz’s Model Dairy is listed in the 1915 NYC Telephone Directory located at Union Course Long Island. (Union Course was part of Woodhaven) The following year, on September 7, 1916 the following notice of incorporation appeared in the Brooklyn Daily Eagle:
Schwartz’s Dairy, Inc., of Queens was chartered today with $10,000. capital, to deal in milk, butter, cream and cheese. David C. and Rose Schwartz of Union Course and Bessie Greenbaum of Manhattan are directors.
A similar incorporation notice in another publication listed the Schwartz’s address as 240 Drew Avenue (now 75th Street) in Woodhaven.
In 1920, census records indicate that David C. and Rose lived on a dairy farm located on Juniper Swamp Road in Middle Village Queens and later, in 1930 and 1940 on a farm on Caldwell Avenue, also in Middle Village. Both farms were run by members of the Schwartz family. Based on this I assume that they were bottling and selling/delivering milk for one or both of these farms as early as 1915.
The Schwartz Dairy, Inc. was apparently the predecessor of the Elmhurst Dairy that was started in 1919 by two members of the Schwartz family, Max and Arthur Schwartz. Elmhurst Dairy is listed as early as the 1922 Copartnership and Corporation Directory for Brooklyn and Queens and remained in business through 2016.
The bottle I found is a machine-made quart. It’s heavily sun-purpled indicating the presence of manganese dioxide which was predominantly used as a decolorizing agent prior to 1920.This supports a manufacture date right around the time of incorporation in the 1915-1920 range.