Mattins has three nocturns and nine lessons. The invitatory, hymn, antiphons and psalms are those used for the Circumcision. In the first nocturn the lessons are from the Epistle to the Romans with the responsories from the Circumcision. In the second nocturn the lessons are from a sermon by St. Augustine and in the third nocturn the homily is from St. Jerome's commentary on the second chapter of St. Matthew's Gospel. At Lauds and the Hours again the antiphons are those from the Circumcision, the antiphon on the Benedictus and collect are proper and a commemoration is sung of St. Telesphorus Pope & Martyr.
At the Hours the antiphons of Lauds are sung and the psalmody is festal (at Prime Pss. 53, 118(i), 118(ii). The hymns of the Little Hours are sung with the Doxology and melody in honour of the Incarnation.
At Mass the Gloria is sung, the second collect is of St. Telesphorus, the third collect of the BVM, Deus, qui salutis. The Credo is sung and the preface is of the Nativity.
Vespers are first Vespers of the Epiphany. For the feast and its octave a Doxology in honour of the LORD's manifestation is sung at all hymns of Iambic metre: Jesu, tibi sit gloria, Qui apparuisti Gentibus, Cum Patre, et almo Spiritu, In sempiterna saecula.
In the 'liturgical books of 1962' the Vigil is abolished and the day is another feria of Christmastide. Mattins has one nocturn and three lessons. St. Telesphorus is commemorated at Lauds and said Masses. The hymns of the Little Hours are sung without the Doxology of the Incarnation. Vespers are the same as the Old Rite.
The Vigil and the Sunday between January 1st and the Epiphany have become fused in the 1570 missal and its successive editions. The celebration of the Octave Days of the comites Christi feasts as doubles meant that the Sunday, under the 1568-1911 rubrics, was moved until the first free day, the 5th and day of the ancient Vigil. Examining older books one can find two sets of formularies: one for the vacant Sunday with the collect Omnipotens as used today and one for the 'real' Vigil with the collect Corda nostra. These, distinct, celebrations were also found in Sarum practice and its closest surviving modern descendant the Dominican rite. With the 1911-13 reform reducing the rank of the comites Christi Octave Days the 'real' Sunday had the Feast of the Holy Name transferred from the Second Sunday after the Epiphany to the Sunday before the Epiphany or January 2nd. The 1948 Commission for General Liturgical Reform clearly didn't understand this and stated '..La vigilia ha semplicemente la liturgia della domenica dope il Natale..'
A Vigil Mass of the Epiphany has been restored in the 2002 edition of the new Roman Missal. The 2002 MR gives the collect as:
Corda nostra, quaesumus, Domini, tuae majestatis splendor illustret, quo mundi hujus tenebras transire valeamus, et perveniamus ad patriam claritatis aeterne.
The Missal of Robert of Jumièges, a favourite of mine, gives the following version for the Vigil:
Corda nostra quaesumus Domine venturae festivitatis splendor illustret, quo mundi hujus tenebris carere valeamus, et perveniamus ad patriam claritatis aeterne.
Another example of where some scholarship after Vatican II was of a higher calibre than that of the 1948 Commission?