Which interpretation(s) of the book of Revelation did the church fathers who accepted it into the canon hold?

Given that the book of the Revelation was the last one to be written (by the apostle John, circa. 95 A.D.) it would be the last one to be accepted as most of the other New Testament writings had already been seen as canonical. Yet given that the Revelation was sent to seven congregations in Asia Minor before the start of the second century, the only problem with it being officially accepted as canonical would come from those who were alarmed at its highly symbolic nature. Yet given how the OT books of Daniel and Ezekiel etc. were strikingly similar re. prophecy, Christians who knew the OT would see that it was in the same genre.

The main problem re. canonicity was with Gnostic literature that purported to be authentic, but was not. Serapion, bishop of the church in Antioch (circa. 190-203) complained that The Gospel of Peter was being read as Scripture in some churches, yet it had docetic ideas of Christ, downplaying or denying his physical reality. Also, some other writings were good and by accredited Christian writers, but did not have the Holy Spirit inspired hallmark of the others. They were often read, but never formed part of the canon. Further, although the official canon was 'closed' by 376, that was just confirmation of what had long been held. Here is a link dealing with that: https://www.gotquestions.org/New-Testament-canon.html

The main question is really, "Which interpretation of Revelation did the earliest Church Fathers have?" The best way to answer that would be to find out what the recipients of John's letter thought. The first seven congregations had to take to heart Christ's warnings (and encouragements) addressed to them personally. Well, we just don't have anything on that. But we do know what the early Church was enduring with persecutions and conflicting teachings, already doing the rounds back then. To read the Revelation in light of their situation would give great understanding. They had no idea for how long they would have to endure till Christ returned but clearly the whole book was to help them remain faithful in an increasingly hostile Roman empire, till Christ suddenly came.

The problem of interpretation arises due to centuries passing and still no second coming of Christ. This means that Christians from the fourth century on would be developing different ways to understand the highly symbolic message. Here is a summary of the main schools of interpretation as in this book:

The Contemporary [Praeterist] Interpretation: This puts the entire book into past history. It views the Revelation as having been fulfilled in the early ages of the church. This interpretation places every event throughout the narrative as contemporary with the first century. [This would be the view of the earliest Church Fathers.] But a device underlies this interpretation. At the time of the Reformation the reformers identified the papacy and its political influence with the beasts in Revelation. This was of great influence. However, the Contemporary Interpretation robbed the reformers of such an application. According to the Contemporary, or Praeterist interpretation, the whole book had long been fulfilled.

The Historicist Interpretation: This views the Book of the Revelation – with the exception of the prologue and the epilogue – as a continuous unfolding of the history of the church in the world. Therefore the narrative answers in sequence to the history of the church, or of the world, or both. This interpretation commences with the apostolic age and continues to unfold to the end of time. There was no difficulty therefore in this interpretation of identifying the ‘Beast’ with the papacy, or with its influences over the worldly powers. This was the view of the reformers. At first Rome and its satellite European Community countered this view with the Contemporary Interpretation. Then a more subtle concept began to be put forth by the papacy.

The Futurist Interpretation: There can be little or no question that this view was developed as Roman Catholic counter-reformation propaganda, the Contemporary, or Praeterist, Interpretation having failed in its attempt to refute the reformers’ Historicist explanation… The Futurist Interpretation, however, put everything in the future, robbing the reformers of their ammunition at a stroke.

The Futurist Interpretation views the church prophetically from the day of Pentecost till the second coming of Christ in historical sequence throughout Chapters 2 and 3 of the book. In Chapter 4:1 a secret rapture of the church is proposed… It follows therefor that the prophetic narrative of events from Chapter 4 to Chapter 20 have nothing to do with the church. It is presumed that this is to do with Israel over a future seven year period of tribulation. In Chapter 20 the thousand years are taken literally, assuming Israel on earth, and the church suspended above it in heaven for the entirety of this period…

This astounding scheme was recovered from oblivion – the Reformation by then seeming to be of little consequence – largely by the ecumenical meetings for prophecy at the castle of Lady Powerscourt in Ireland. J.N. Darby and other early brethren leaders, many of them clergymen, featured prominently. The Plymouth Brethren adopted and propagated this originally papist subterfuge with great vigour from the 1830’s onward. After the division at Plymouth, the American Schofield had the temerity to incorporate this papist propaganda, with other horrific schemes, such as dispensationalism, interleaving such things so as to add them to the Holy Bible, newly dubbed ‘The Schofield Bible’.” The Revelation of Jesus Christ by John Metcalfe, pp 13-15 (published 1998)

He then details The Resumptive [or Spiritual] Interpretation, which he holds to, where the entire age of the church is revealed seven times over, culminating in the last judgment, each presentation adding more details and principles to the monumental struggle between the church on earth and the demonic, invisible powers trying to crush her, to this day. He points out that Rev. 2:10 (the church in Smyrna) had, in those days, the faithful martyr Antipas, and such persecution would continue till Christ returned (p 47). Thus, the message to the seven churches speaks to the persecuted saints in every age from Christ giving the Revelation, to his sudden appearing.

He makes clear that Christians holding to the Resumptive [Spiritual] Interpretation are aghast at that of the Futurists. Nor did the Reformation Historicist view uphold the 1800’s ideas of the Futurists. Both those groups maintained that “The Last Days” had begun in the 1st century A.D. and continue to this very day – Hebrews 1:1-2.

This answer may appear to go beyond the remit of the question, but due to gradual developments over the centuries, only this over-view shows the early Church Father's interpretation, which then had to be 'adjusted' once the Reformation challenged this view that it had all happened in the past. The 'adjusted' interpretation is (ironically) held by many Protestants! It is the prevailing view today but it certainly was not the view of the earliest Christians or of the earliest Church Fathers because they expected Christ's return very soon. Only with the passage of a few hundred years would it be obvious that claiming, "It all happened in the past" just no longer held water.