One obvious difference between the two Eastertides of the usus antiquior and usus recentior is the size of each of them. The 1962 Missal has proper Masses for each Sunday after Easter, as well as each day in the Octave of Easter and for the Ascension. In the 2008 Missal, however, all the Sundays and weekdays within Eastertide have proper Masses assigned to them, with collects unique to each day. [1]
Given this, one might have thought that the corpus of Eastertide orations in the older Missal would have been carried over directly into the newer Missal, and supplemented with other Eastertide prayers from the vast repository of the Church’s liturgical tradition. However, as seems to be the case with so much of the post-Vatican II reforms, this is at best only half-true. Some prayers have been edited in ways completely unknown in their manuscript history; others with a long tradition of use in particular times of the liturgical year have been moved to where they have never been used before; still others have been freely combined with one or more other prayers to create novel and original texts.