I'm working on some Universalist liturgy projects and have been keenly feeling both the generations of lost ecumenical interchange, and the lost reasoning that lead to the texts we do have. So I decided to read some older works to fill in the missing pieces with the goal of working towards the present.
I happened across "The Reform of Liturgical Worship Perspectives and Prospects" (The Bohlen Lectures 1959) by Massey Hamilton Shepherd, Jr.
This gave me a sense of the development of American Episcopalian liturgical development from the Ritualists to his own time, halfway between the prayer book revisions of 1928 and 1979.
And it it, I found a reference to the 1867 The Book of Common Prayer: as amended by the Westminster Divines, A.D. 1661, also known as the Presbyterian Book of Common Prayer by Charles W. Shields, but particularly the appended essay Liturgia Expurgata which fills in for that work a lineage that I wished the contemporary (1866) Universalist A Book of Prayer for the Church and the Home had. Indeed, I wonder if it was on the desks of those Universalists, especially Charles Hall Leonard, who developed the longer-lasting tradition of Universalist prayer books that ran in successive editions and abridgments through the 1950s.