Holgar Peter Sandhofe (Gerolitus Ammosaulicus) was a master typesetter of chant and the producer of many electronic editions once distributed on nocturnale.de, which is now off line. Among his work are an editions of the following:
Matins Ferial Psalms with Antiphons (Pre-Pius X Psalter--1909 Breviary)
Matins Ferial Psalms with Antiphons (Post-Pius X Psalter--1962 Breviary)
Matins of Advent
Matins for the Commons of Saints
Festival Office of St. Martin de Porres
Invitatory Antiphons and Psalms for all Sundays
Gospel Canticles of Lauds and Vespers in the 8 Tones
Prolix Responsory Cycle for Ferial Weekdays
Ordinary of the Dominican Office
Appendix of New Chants for the Graduale (post-1962)
I have recently been able to locate these hard to find projects and am now making them available. Downloadable files of all this music is now available on the left sidebar at Dominican Liturgy.