The letter Romans is included in Marcion’s collection of 10 Pauline letters as found in Tertullian’s Adv. Marc. And in Book 5 of Adv. Marc., many passages from the letter we know as Romans are discussed by Tertullian.
But in Tertullian’s Adv. Marc., I haven’t found any clear reference to a Pauline letter written to “Rome”. I haven’t waded through all of Tertullian’s verbiage --- perhaps I missed something.
In Book 5, Tertullian explicitly mentions by the destination or the designation of the letters, only Galatians (ch. 2), Ephesians/Laodiceans (ch. 17), and to “one man”, i.e. Philemon (ch. 21). However, Tertullian cites text from 9 of the 10 letters attributed to Paul, lacking only text from Philemon.
Tertullian, in his polemics against Marcion, discusses the text of the letter now known as Romans in Book 5, chapters 13-14 of Adv. Marc. However, the only places in Romans where any mention of a Roman address are found (1:7a, 1:15, and chapter 15) are unattested by Tertullian in Adv. Marc. (i.e., not mentioned). Other textual evidence demonstrate inconsistencies in those same passages.
In Book 4, Tertullian rounds out the names of the locales in which he understood the existence of Pauline congregations ---
… it will certainly be quite as evident, that comes down from the apostles, which has been kept as a sacred deposit in the churches of the apostles. Let us see what milk the Corinthians drank from Paul; to what rule of faith the Galatians were brought for correction; what the Philippians, the Thessalonians, the Ephesians read by it; what utterance also the Romans give, so very near, to whom Peter and Paul conjointly bequeathed the gospel even sealed with their own blood. (Adv. Marc., Book 4, ch. 5)
The characterization of Paul’s role is quite different for the Roman audience here. The Corinthians drank Paul’s milk, the Galatians were corrected; and the Philippians, the Thessalonians, and the Ephesians read by it.
But for the Romans, it’s the gospel that was bequeathed to them conjointly by Peter and Paul as sealed by their own blood, per Tertullian and other early-catholic legends.
Also according to early-catholic legend, the Gospel of Mark was composed in Rome. Tertullian explicitly credits Mark as the interpreter of Peter, and Luke’s Gospel is ascribed to Paul ---
The same authority of the apostolic churches will afford evidence to the other Gospels also, which we possess equally through their means, and according to their usage--I mean the Gospels of John and Matthew--whilst that which Mark published may be affirmed to be Peter's whose interpreter Mark was. For even Luke's form of the Gospel men unusually ascribe to Paul. (Adv. Marc., Book 4, ch. 5)
I have found nothing in Tertullian’s Adv. Marc. that clearly references a Pauline letter addressed to Rome. Am I missing something?