Does Irenaeus Let it Slip Out that He Was the Real Author of the Cento Gospels of the Commodian Age (= Our Canonical Gospels)?

All we have to do is follow Unger's notes to his translation of Irenaeus's Against the Heresies volume 1 p. 182. The original section in Irenaeus introduces a Homeric cento which many scholars see as Irenaeus's own composition:

Then, again, collecting a set of expressions and names scattered here and there [in Scripture], they twist them, as we have already said, from a natural to a non-natural sense. In so doing, they act like those who bring forward any kind of hypothesis they fancy, and then endeavour to support them out of the poems of Homer, so that the ignorant imagine that Homer actually composed the verses bearing upon that hypothesis, which has, in fact, been but newly constructed; and many others are led so far by the regularly-formed sequence of the verses, as to doubt whether Homer may not have composed them. Of this kind is the following passage, where one, describing Hercules as having been sent by Eurystheus to the dog in the infernal regions, does so by means of these Homeric verses,-- for there can be no objection to our citing these by way of illustration, since the same sort of attempt appears in both:--

Thus saying, there sent forth from his house deeply groaning.
The hero Hercules conversant with mighty deeds.
Eurystheus, the son of Sthenelus, descended from Perseus.
That he might bring from Erebus the dog of gloomy Pluto.
And he advanced like a mountain-bred lion confident of strength.
Rapidly through the city, while all his friends followed.
Both maidens, and youths, and much-enduring old men.
Mourning for him bitterly as one going forward to death.
But Mercury and the blue-eyed Minerva conducted him.
For she knew the mind of her brother, how it laboured with grief.

Now, what simple-minded man, I ask, would not be led away by such verses as these to think that Homer actually framed them so with reference to the subject indicated? But he who is acquainted with the Homeric writings will recognise the verses indeed, but not the subject to which they are applied, as knowing that some of them were spoken of Ulysses, others of Hercules himself, others still of Priam, and others again of Menelaus and Agamemnon. But if he takes them and restores each of them to its proper position, he at once destroys the narrative in question. In like manner he also who retains unchangeable in his heart the rule of the truth which he received by means of baptism, will doubtless recognise the names, the expressions, and the parables taken from the Scriptures, but will by no means acknowledge the blasphemous use which these men make of them. For, though he will acknowledge the gems, he will certainly not receive the fox instead of the likeness of the king. But when he has restored every one of the expressions quoted to its proper position, and has fitted it to the body of the truth, he will lay bare, and prove to be without any foundation, the figment of these heretics.

Unger's endnote for the Homeric cento is very interesting and reads as follows:

These lines are respectively from Homer's Od. 10.76; Od. 21.26; ll. 19.123; Il. 8.368; Od. 6.130; Il. 24.327; Od. 11.38; Il. 24.328; Od. 11.626; Il. 2.409. This manner of quoting from all sections of Homer's two works is thought by some to indicate that Irenaeus had a personal and rather close acquaintance with Homer. And really Irenaeus does not say that he is copying from someone else. His construction clearly supposes that he is the composer of the cento. He uses a present participle (scribens] in a conditional sense, "if one would write," just as in a previous sentence he wrote "like those who would propose": similia facientes. The construction is the same in the Greek. Further, his remarks after the poem also betray competence in Homer. Irenaeus knew the classics. He refers to and quotes Homer in AH 1.12.2; 1.13.6; 2.5.4; 2.'4.2, 2.22.6; 4.33.3. Other poets to whom Irenaeus also refers include Anaxilas, Hesiod, Pindar, Antiphanes, Menander, Sophocles, Stesichorus, and the Comic poets in general. On this see AI I. 1.13.1; 1.23.2; 2.14.1; 2.14.2; 2.14.4; 2.'4.5; 2.18.5; 2.21.2; 5.13.2; cf. WR Schoedel, "Philosophy and Rhetoric in the Adversus haereses of Irenaeus," VC 13 (1959) 22-32, and M. Clark, "Builders of the Christian Culture: A Study of Irenaeus of Lugdunum and Clement of Alexandria," Ph.D. diss., Harvard University, 1970, passim. Homer was the backbone of Hellenistic education, and, among the early Christians, Homer was a topic of discussion and controversy. But the Gnostics also used him; he was the prophet of the Valentinians (cf. 4.33.2)Hippolytus accuses them of falsifying Homer (cf. Haer. 6.19.1 [GCS 26.145]). Rousseau (SC 263.222 [SC 264.149 n. 1]) also notes that some have thought Irenaeus himself wrote this cento, notably H. Ziegler, Irenaus der Bischof von Lyon (Berlin 1871) 17. J. Danielou, The Gospel Message and Hellenistic Culture, vol. 2 of A History of Early Christian Doctrine before the Council of Nicaea, trans. JA Baker (London and Philadelphia 1973) 85, thinks that Valentinus himself composed this cento and that he gave it an allegorical meaning in reference to the Gnostic tenets, particularly in regard to the sending of Savior who is surrounded by angels and accompanied by Christ and the Holy Spirit. RL Wilken, "The Homeric Cento in Irenaeus, 'Adversus haereses' I,9,4," VC 21 (1967) 25-33, doubts that Valentinus wrote it and gave it this alleged allegorical meaning, since Irenaeus gives no such indication, and he quickly forgets about the cento. He wished merely to show how the Gnostics misinterpret Scripture by distorting the passages when lifting them from their context. Benoit 6o-61, flatly denies that Irenaeus wrote this cento.

The point of course is that given that Irenaeus identifies a contemporary accusation (his own) that Christians in the age were creating gospels after the manner of Homeric centos (see AH 1.8.1) the fact that he is apparently so skilled in creating centos makes him a prime suspect for refashioning from Secret Mark into the canonical gospels (see Morton Smith's discussion in Clement of Alexandria and a Secret Gospel of Mark).