In May I wrote
a blogpost about two leaves from a Book of Hours which has the initials "MdM" and "AdM" -- presumably of its husband and wife owners -- in the borders; they are at Montreal and Rochester, NY. By chance I found another leaf from the same manuscript while in the US in July, in Toledo, Ohio, and wrote
another blogpost about them after my return. In the second of these posts I reproduced a page from a 1923 Maggs Bros catalogue, in which four leaves of the manuscript are described, including the Toledo one.
I have now found two more leaves, at least one of which is described in the Maggs catalogue. The two new leaves do not have the telltale initials "MdM" and "AdM" in their borders, but I am confident -- based on the style of script and decoration, and the number of lines per page -- that they come from the same manuscript.