Beacon Press
Wikipedia: https://en.wikipedia.org/wiki/Beacon_Press
Archives: Harvard Divinity School, Andover-Harvard Theological Library has multiple special collections: Beacon Press. Books, 1866-, Beacon Press. Records, 1952-1973, Beacon Press. Records, 1935-1988, Beacon Press. Records, 1935-1981, Beacon Press. Records, 1981-1994; Arnold, Melvin. Papers, 1945-1956., Harvard Divinity School, Andover-Harvard Theological Library, https://hollisarchives.lib.harvard.edu/repositories/12/resources/849.
Harvard Divinity School's Andover-Harvard Theological Library has a few special collections of Beacon Press Records:
Here is a 1967 Beacon Press Catalog:
https://archive.org/details/TNM_Hardcover_books_from_Beacon_Press_Spring_1967_20171011_0104/ (listing, at end, BP 1 to BP 238, BP A-D & BP S, and LR 1 to LR 20, except LR 3 & LR 11)