As you can see, someone is doing research on a relative. Henry Birkenstock garners only a brief mention in Bob Jones "Biographical Index of American Stained Glass Makers".....in business during 1923 in NYC. Anyone else have information? A Google search found mention of one church in New Jersey with windows by this firm, but that was all. I have contacted the person making the inquiry to see if he has any additional information.
"Am looking for any information you might have on my Great Uncle, Henry Birkenstock, whose Art Glass Studio was in Mount Vernon and who was responsible for many windows in churches, schools, and public buildings across the country and in Cuba, Mexico and South America."