Does Victor of Vita quote from the Three Heavenly Witnesses?

Victor of Vita lived in Roman Africa after its conquest by the Vandals.  The Vandals were Arians, and their kings persecuted the Catholic clergy.  In 484 Victor wrote an account of the persecutions, which has come down to us in a number of manuscripts.  These I list from C. Halms 1878 edition in the Monumenta Germanica Historiae, series: Auctores Antiq., vol. 3.1. Online here.  There is also the CSEL 7 edition by Petschenig (1881).

• A = Laon, Codex Laudunensis 113 (9th c.)  Contains only book 2, and a list of Catholic bishops at the synod of 484, which alone is preserved in this copy.  Another used by an early editor no longer seems to exist.
• B = Bamberg, Codex Bambergensis signatus E, 3, 4. (9th c.)
• C = Upper Austria, Codex monasterii Cremifanensis, sign. 36 (12th c.)
• L = Berlin, Codex Berolinensis lat. quart. 1. (12th c.)
• M = Munich, Codex Monacensis 2545 (previously cod. Alderspacensis) (12th c.)
• P = Paris latinus 2015 (once Colbertinus 905)(10th c.)
• R = Brussels, Codex Bruxellensis 1794. (10th c.)
• V = Vienna, Codex Vindobonensis 583 (previously “Univ. 239”)(10th c.)
• W = Vienna, Codex Vindobonensis 408 (formerly Admontensis from the abbey of Admont) (11th c.).  Contains some crude interpolations.  Derived from V.
• a = Codex Abrincensis 162 (12th c.) Both mutilated and interpolated.
• b = Berne, Codex Bernensis 48. (Once Floriacensis)(11th c.)  Similar to R but inferior.
• s = Admont, Codex Admontensis 739 (12th c.).  Derived from V.

Analysis of the readings means that the manuscripts fall into two families, both derived from O, the original now manuscript (manuscripts in Greek letters are lost ancestor manuscripts of one family or another).  The tree of which manuscript was copied from what (the stemma) looks like this:

The editio princeps, the first edition is actually “Parisiis ab Iano Parvo (=Jehan Petit) Ludovico XII. regnante impressa”.  This undated edition was unknown to editors who generally thought that this was the edition of Beatus Rhenanus at Basle in 1535.

There is a modern English translation in the Liverpool University Press series: Victor of Vita: History of the Vandal Persecution, tr. John Moorhead, Liverpool (1992); series: Translated Texts for Historians 10.

The passage that refers to the Comma Johanneum, the interpolated passage in 1 John 5:7 which discusses the Trinity, is in book 2, chapter 11 (section 82; p.34 of the edition).  Halms’ edition (which Moorhead translated) reads:

82. Vnde nullus ambiguitatis relinquitur locus, quin clareat spiritum sanctum et deum esse et suae voluntatis auctorem, qui cuncta operari et secundum propriae voluntatis arbitrium divinae dispensationis dona largiri apertissime demonstratur, quia ubi voluntaria gratiarum distributio praedicatur, non potest videri condicio servitutis: in creatura enim servitus intellegenda est, in trinitate vero dominatio ac libertas. Et ut adhuc luce clarius unius divinitatis esse cum patre et filio spiritum sanctum doceamus, Iohannis evangelistae testimonio conprobatur.  Ait namque: tres sunt qui testimonium perhibent in caelo, pater, verbum et spiritus sanctus, et hi tres unum sunt. Numquid ait: tres in differenti aequalitate seiuneti aut quibuslibet diversitatum gradibus longo separationis intervallo divisi? sed, tres, inquit, unum sunt.

The CSEL text is the same, and the apparatus contains only trivial variants.

This is rendered by Moorhead (p.56):

82 And so, no occasion for uncertainty is left. It is clear that the Holy Spirit is also God and the author of his own will, he who is most clearly shown to be at work in all things and to bestow the gifts of the divine dispensation according to the judgment of his own will, because where it is proclaimed that he distributes graces where he wills, servile condition cannot exist, for servitude is to be understood in what is created, but power and freedom in the Trinity. And so that we may teach the Holy Spirit to be of one divinity with the Father and the Son still more clearly than the light, here is proof from the testimony of John the evangelist. For he says: ‘There are three who bear witness in heaven, the Father, the Word and the Holy Spirit, and these three are one.’ Surely he does he not say ‘three separated by a difference in quality’ or ‘divided by grades which differentiate, so that there is a great distance between them?’ No, he says that the ‘three are one.’

That’s that, pretty much; this 5th century Latin text definitely mentions the Three Heavenly Witnesses as part of the text of 1 John.

Moorhead adds a comment on the text of scripture used by Victor (p.xix ff.):

To avoid a multiplication of footnotes I have supplied references to biblical quotations and allusions in parentheses, without troubling to register minor ways, whether due to the text which Victor or the authors of the Book of the catholic faith were familiar with, faulty memory, or some other cause, in which they differ from modern printed versions of the Bible. The chapter and verse numbers of the psalms are those of the Vulgate, but the names of books of the Bible are those by which they are generally known in English. Where ‘Vulg’ is added, the text Victor cites is similar to the Vulgate and differs significantly from the modem translations readers may have at their disposal; where ‘cf’ is added, Victor’s text is significantly different from both the Vulgate and modem versions.[23]

The footnote:

23. It must be said that some of the variants which occur in the Book of the catholic faith constitute amendments in a Trinitarian direction.

It is perhaps inevitable in the circumstances, if undesirable, that the most useful reading was preferred.