It's hard to find the works of James Relly, John Murray's mentor and Judith Sargent Murray's inspiration. His influence was on a terminal decline within the Murrays' lifetime, and later reprints were largely of historical interest. But I'm rather keen on him, or at least the fragments I've found. I've republished as a PDF his Union: or, a Treatise of the Consanguinity and Affinity between Christ and his Church. (1759)
Today I found Thoughts on the cherubimical mystery, or, An attempt to prove that the cherubims were emblems of salvation by the blood of Jesus (1780, 1808 ed.) not through Google Books, but through Archive.org, from the original at Boston Library. I've not read it yet, so leave it to the wide eyes of a wondering public.