Roman ritual books, both modern, from before the council, or ancient, would all be helpful!
A bundle of the current English and Latin ritual books would be awesome. Particularly since the Latin editions can be hard to come by. There is also no study edition of the English of Ordination because Liturgical Press has never updated there Rites I and II to use the new translation.
The 62'ish ritual here would also be nice: http://smile.amazon.com/Roman-Ritual-3-Volume-Set/dp/B000UWJ91O?sa-no-redirect=1