I know Kathy Pluth has done one or more . . . should be on her site somewhere:

http://hymnographyunbound.blogspot.com/

I almost forgot this one, which is the Lauds hymn proper to the feast itself, St. Ambrose's Apostolorum Passio. Like those in the CanticaNOVA article, it's in Ambrosian meter, 8888 (LM) iambic. Jesu dulcis memoria is a well-known chant tune that would work well, although to my ears, this one sounds best to Deo Gratias.

Blest day by suff’ring sanctified:
Christ’s chosen high apostles died.
Today St. Peter wins renown.
Today St. Paul accepts the crown.

Together, equally, they bled:
Together: the victorious dead.
They followed God and sacrificed
And now their faith is crowned by Christ.

St. Peter holds the highest place,
Yet Paul is not the less by grace.
An equal faith was giv’n to Paul:
The chosen vessel of God’s call.

St. Peter, downward crucified—
To honor God in how he died—
Securely tied, he sees unfold
The death his Shepherd once foretold.

On such foundations Rome may claim
The highest service of God’s name.
His noble blood has dignified
The city where this prophet died.

Let all the world, then, run to Rome.
Let families of nations come!
The head of nations teaches there
Beside the nations’ teacher's chair.

O Lord, we ask that we may be
In their exalted company,
And with our princes sing Your praise
Forever, to unending days.

Apostolorum passio
diem sacravit sæculi,
Petri triumphum nobilem,
Pauli coronam pæferens.

Coniunxit æquales viros
cruor triumphalis necis;
Deum secutos præsulem
Christi coronavit fides.

Primus Petrus apostolus;
nec Paulus inpar gratia,
electionis vas sacræ,
Petri adæquavit fidem.

Verso crucis vestigio
Simon, honorem dans Deo,
suspensus ascendit, dati
non inmemor oraculi.

Hinc Roma celsum verticem
devotionis extulit,
fundata tali sanguine
et vate tanto nobilis.

Huc ire quis mundum putet,
concurrere plebem poli:
electa gentium caput,
sedes magistri gentium.

Horum, Redemptor, quæsumus,
ut principum consortio
iungas precantes servulos
in sempterna sæcula.

(bumping for the feast)

O Light from Light, all ages show
Your beauty, and the martyrs fame,

Love it. Not enough writers are willing to let grammar structures span, hemiola-like, the metrical framework. And too many that do, do it poorly. Something about just this one little moment here I really appreciate.

The heavens' porter, and earth’s sage,

how about "earth's own sage" to get the accent on the right syllable?
(Although that looses "and" which makes it sound like two titles for one person.

Anyway- something must be done here, I think.)

Perhaps there's a better word for "porter." I know what you're getting at (and, I assume, what the original is getting at), as heaven's "doorkeeper," but I suspect that the remaining few English speakers who actually know the word associate it primarily with the carrying of objects or the assistance of passengers.

One wins by cross, and one by sword,

love it.

Full fonts, in your matched charity,

Very mouthy.
I have no suggestion, because I'm not sure what these words are getting at.

Pray that we may in heaven be.

I do not know why, and there's nothing wrong with this as it is, but for some reason I would personally prefer:
"Pray that in heaven we may be."

And joy and pow’r, for their reign stays
Today and through all endless days.

Something in the rhythm not quite working for me. I think because even though "pow'r" is theoretically one syllable, its quite a long syllable and butts into the next syllable, which pushes back, being a Phat consonant.
What about transposing- "pow'r and joy" ? Having a vowel after "pow'r" fixes it (for my ears at least).

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It's lovely.

Bumping for the feast.

(bump)

:-(
sorry to hear that, Kathy. (yes, this is a timely bump.)