You’re right. The Early Church had significantly more. Both epistles from other Bishops, and added books in the OT.
Many books were circulated throughout the universal (catholic) Church, before 393 A.D.
Here are a few that were widely circulated and often disputed. I think that you may be surprized not only what books were “in” but what books were often left “out”
Shepherd of Hermas
The Shepherd of Hermas (Greek: Ποιμήν του Ερμά; Hebrew: רועה הרמס; sometimes just called The Shepherd) is a Christian literary work of the 1st or 2nd century, considered a valuable book by many Christians, and considered canonical scripture by some of the early Church fathers such as Irenaeus. The Shepherd had great authority in the 2nd and 3rd centuries. Along with the Apocrypha, it was bound with New Testament in the Codex Sinaiticus, and it was listed between the Acts of the Apostles and the Acts of Paul in the stichometrical list of the Codex Claromontanus.
Didache
The Didache ( /ˈdɪdəkiː/; Koine Greek: Διδαχή) or The Teaching of the Twelve Apostles (Didachē means “Teaching”) is a brief early Christian treatise, dated by most scholars to the late first or early 2nd century. The first line of this treatise is “Teaching of the Lord to the Gentiles (or Nations) by the Twelve Apostles” (Διδαχὴ κυρίου διὰ τῶν δώδεκα ἀποστόλων τοῖς ἔθνεσιν).
The text, parts of which constitute the oldest surviving written catechism, has three main sections dealing with Christian ethics, rituals such as baptism and Eucharist, and Church organization. It is considered the first example of the genre of the Church Orders.
The work was considered by some of the Church Fathers as part of the New Testament
Epistle of Barnabas
The Epistle of Barnabas (Greek: Επιστολή Βαρνάβα, Hebrew: איגרת בארנבס) is a Greek epistle containing twenty-one chapters, preserved complete in the 4th century Codex Sinaiticus where it appears at the end of the New Testament. It is traditionally ascribed to Barnabas who is mentioned in the Acts of the Apostles, though some ascribe it to another Apostolic Father of the same name, a “Barnabas of Alexandria”, or simply attribute it to an unknown early Christian teacher. A form of the Epistle 850 lines long is noted in the Latin list of canonical works in the 6th century Codex Claromontanus. It is not to be confused with the Gospel of Barnabas.
Toward the end of the 2nd century Clement of Alexandria cites the Epistle. It is also appealed to by Origen of Alexandria. Eusebius, the first major church historian, however, recorded objection to it, see Antilegomena, and ultimately the epistle disappeared from the appendix to the New Testament, or rather the appendix disappeared with the epistle. In the West the epistle never enjoyed canonical authority (though it stands beside the Epistle of James in the Latin manuscripts). In the East, the Stichometry of Nicephorus, the list appended by the 9th century Patriarch of Jerusalem to his Chronography, lists the Epistle of Barnabas in a secondary list, of books that are antilegomena— “disputed”— along with the Revelation of John, the Revelation of Peter and the Gospel of the Hebrews.
Epistles of Clement
The First Epistle of Clement, (literally, Clement to Corinth; Greek, Κλήμεντος πρὸς Κορινθίους, Klēmentos pros Korinthious) is a letter addressed to the Christians in the city of Corinth. The letter dates from the late 1st or early 2nd century, and ranks with Didache as one of the earliest — if not the earliest — of extant Christian documents outside the canonical New Testament. As the name indicates, also a Second Epistle of Clement is known, but this is a later work, not by the same author. In the case of the first epistle the scholarly consensus is overwhelmingly in favour of its authenticity, whereas by contrast it is widely accepted that the second epistle is not to be attributed to Clement. Many scholars believe 1 Clement was written around the same time as the Book of Revelation, c. 95-97 AD. Neither 1 nor 2 Clement was accepted in the canonical New Testament, but they are part of the Apostolic Fathers collection.
The Second Epistle of Clement, (literally, Clement to Corinth; Greek, Κλήμεντος πρὸς Κορινθίους, Klēmentos pros Korinthious) often referred to as 2 Clement, is an early Christian writing. 2 Clement was not accepted in the canonical New Testament, but was included in the Apostolic Fathers collection.
2 Clement was traditionally believed to have been epistle to the Christian Church in Corinth written by Clement of Rome sometime in the late 1st century. However, 4th-century bishop Eusebius, in his historical work, says Clement “has left us one recognized epistle”, so doubts about this work belonging to Clement of Rome are not new. Modern scholars believe that Second Clement is actually a sermon written around 140–160 CE by an anonymous author – one who was neither the author of 1 Clement nor Clement of Rome. Nonetheless, scholars still generally refer to the work by its traditional name “Second Clement”.