Fair enough. You might find this passage of more interest. Taken from the Muratorian fragment, it is thought to been written by St. Hippolytus of Rome (the first antipope)somewhere around the year 200. The excerpt pertinent to your question is as follows:
"The Epistles of Paul, however, for those who wish to understand the matter, indicate of themselves from what place and for what cause they were sent. First of all he wrote to the Corinthians, to check schismatic opinions, then afterwards a second; to the Galatians about circumcision; to the Romans, however, at some length, about the order of Scriptures, and also to show that Christ is foremost in them. It is not necessary for us to discuss them separately, since the blessed Apostle Paul himself followed the order of his predecessor, John, and wrote to only seven Churches by name. They are, in this order: first to the Corinthians, second to the Ephesians; third, to the Philippians; fourth to the Colossians; fifth, to the Galatians; sixth, to the Thessalonians; seventh, to the Romans. And indeed, although he writes again to the Corinthians and to the Thessalonians for their correction, nevertheless it is shown that there is one Church spread abroad through the whole world. Besides these, there is one to Philemon, and one to Titus, and two to Timothy, in affection and love, but nevertheless regarded as holy in the Catholic Church, in the ordering of churchly discipline.
The scholar explicitly points out in footnotes that the highlighted text is to be read that Paul’s writing’s are to be regarded as inspired and read ceremonially in the Liturgy. I hope this is a little to closer to what you are searching for.