We can add a few more details about Mr. Brewster.
We never met him, but we did speak several times on the phone, and then corresponded with him.
Mr. Brewster met Serge Taneyev and his wife in New York City in 1935. In 1937 Mr. Brewster went to Finland to visit A. A. Vyrubova, from whom he purchased her photo albums.
He had photographs of Anna and her maid, Vera, at their cottage. He was also a guest of Count and Countess Pahlen, the niece of A. A. Vyrubova and the daughter of her sister, Alya Pistolkhors.
The Pahlens' summer house, "Monrepos" was destroyed during the Russo-Finnish War in 1940.
In 1951 Mr. Brewster presented the Romanov family albums to his alma mater, Yale.
Mr. Brewster never met Lili Dehn, but he corresponded with her in care of Serge.
In 1960 he also purchased Lili Dehn's letters from the Imperial family, and in 1983 he presented those to Yale too.
(It was quite a delightful surprise for us when, during our first visit to Yale's Beinecke Library in order to see A. A. Vyrubova's things, the head librarian, Miss Wynne, casually put Lili's letters on the table, saying: "Perhaps you would be interested in these too?"!)
Mr. Brewster died in 1995 or 96. He was a bit of recluse, and I don't believe that an obituary or biographical article ever appeared on him.
Mr. Louis Auchincloss (1917-2010), the NYC lawyer and author, was his friend and legal advisor. It was Mr. Auchincloss who negotiated the two sales of letters for Mr. Brewster.
After Mr. Brewster's death, Mr. Auchincloss also corresponded with us and told us more details.