This is what the 1943 Yearbook had to say about Beth-Sarim on pages 33-34:
Built in 1929, at San Diego, California, the house named Beth-Sarim has been the focal point of much enemy ridicule because it was deeded to Abraham, Isaac, Jacob, David, Jephthah, and other righteous men of old whom God has promised to make "princes" in His New World. Much publicity has been given to Beth-Sarim, Society property, due to naming it Beth Sarim, which means "house of the princes", in expectation of the resurrection of these faithful men of old to be "princes in all the earth".
It was at this home that Brother Rutherford, the former president of the WATCH TOWER BIBLE & TRACT SOCIETY, finished his earthly course of life, on January 8, 1942. Immediately thereafter considerable publicity was again given the home. It was the wish of the former president to be buried on this property, but the "city fathers", along with the religionists, put up a great howl. The details of the controversy will be found in Consolation No. 592.
The people of good-will in San Diego showed their desire to have Judge Rutherford's wishes complied with, by 14,693 of them signing a petition, but their desires were ignored. By the circulation of this petition a real witness was given in this territory for a period of months.
The brethren living at Beth-Sarim and on property adjoining thereto look after the interests of the Kingdom at that place. A course of study is conducted there similar to that at the Bethel home, under the direction of a competent instructor. Seven brethren that live there and take care of the property spend a great portion of their time in the field service, organizing study groups and caring for the people of good-will.
These provisions of the Lord-the Watchtower farm on Staten Island and the Kingdom farm at South Lansing, New York-make it possible for those working in New York city preparing the publications to have good food, and thus be enabled to carry on their strenuous duties. All of this provision reflects on the good production shown in this year's report from the 117 Adams Street office.
And that's it. Also, this is all mentioned on Beth-Sarim's Wikipedia article.