The suggested assignments for each Mass in the Vatican Kyriale for the TLM are given in the following (1962 revisions in brackets).

Some are based in long-standing practice (Masses I and IX), but you are probably aware that these are only suggestions, and that you are free to "mix and match" among the various parts of each mass: "This Ordinary is NOT meant to be a matter of hard and fast rule: chants from one Mass may be used together with those from others, the Ferial Masses [XVI and XVIII] excepted. In the same way, in order to add greater solemnity, one or more of the following 'Chants ad libitum' may be employed" (Liber Usualis, p. 78).

I - Paschal Time
II, III - Solemn feasts [1st class]
IV - VIII - Doubles [2nd class]
IX, X - Feasts of Our Lady
XI - Sundays throughout the year
XII, XIII - Semidoubles [3rd class]
XIV - Within octaves, except of Our Lady [3rd class]
XV - Simples [Commemorations and ferias of the Christmas season]
XVI - Ferias thoughout the year [The Ite missa est may be used ad libitum for any mass]
XVII - Sundays of Advent and Lent
XVIII - Ferias of Advent and Lent, Vigils Days, Ember Days Rogation

No assigments are given for the Credos, although a note at the end of Credo I states: "This is the authentic tone for the Credo, but the following tones may be used where it is customary."

The 1974 Graduale has the following designations only:

I - Paschal Time (with additional Kyries for Sundays and of Feasts and Memorials)
IV - Feasts of the Apostles
IX - Solemnities and Feasts of Our Lady
X - Feasts and Memorials of Our Lady
XI - Sundays throughout the Year
XVI - Ferias throughout the year
XVII - Sundays of Advent and Lent
XVIII - Weekdays of Advent and Lent, and Masses for the Dead (the latter having its own Kyrie)

The note after Credo I above is retained.

If one uses the Liber Usualis of 1962 one should be careful about the classifications given at the feast locations, since they have not all been updated properly, for instance the octave day of the Nativity, Jan 1, is listed as the equivalent of a Class II at the feast location following longstanding tradition, but in the introduction that describes the new classification scheme, it is given as a Class I feast. Basically one follows the scheme in the introduction, but there are exceptions given in the Kyriale for Class I feasts, such as Sundays and feasts during the Paschal season, Kyries IX and X for feasts of the Blessed Virgin, and Kyrie XVII for Sundays in Advent and Lent.

Does anyone know if the 1963 LU currently published by Preserving Christian Publications was updated properly?

Very Interesting. We typically do IX the entire Christmas season, and if we need it to be shorter depending on the priest we will do X- its a very interesting topic for study- where have these different "traditions" been sourced from? What was done in the past. Then, there is the subject of mixing masses which have sustained evidence according to certain manuscripts....

Speaking of Christmas traditions, Dom Mocquereau had this to say about the Ambrosian Gloria in his Art of Gregorian Music:

It turns upon two or three notes, and a short jubilus. A modern composer would consider it monotonous and insipid, but to me its simplicity is charming, and its frank and wholesome tonality refreshing. That joyous neum has a rustic ring about it that reminds one of the hillsides of Bethlehem and fills me with the joy and peace of Christmastide. It is indeed a song worthy of the angels, those pure spirits, and of the poor shepherd folk.

I suspect that this is influenced by historical research of the 60s and 70s (as many things of the liturgical reform - think of the reform of the breviary which is heavily influenced by the psalm exegesis of the time - which is now outdated). I remember that Ferdinand Haberl notes in his comment on the graduale romanum (1976) that the ordinaries originally did not have any association with seasons plus that the parts of them were put together much after their first appearence. He concludes that one is free to pick any parts of any ordinary for whichever season one wishes - ignoring the later and at least partly very strong associations. I mean can anybody imagine to sing any other ordinary than I in paschal time?

No, I was just quoting Ferdinand Haberl (from my memory) who wrote that in his commentary on the Gradual. I think its a very bad idea and typical for the time around the liturgical reform.