There is an
interesting post at "Reformed Catholicism" (a weblog on ecumenical Calvinism) that looks at Leibniz's reunionism - he attempted to try to find ways for Catholics and Protestants (particularly Lutherans) to reunite through the three works of exposition, deference, and suspension. One very rarely finds any discussion of Leibniz's views (or the views of any other early modern thinker) on this point, which is why I am linking to it.