105. many alleged 'falsifications of Luke' are simply known (western) attestations of 'according to Mark' or even Matthew

this text of Luke which Marcion found in (?) Rome was already assimilated to Matthew and Mark. Harnack gives a list of thirty-four such assimilations in Marcion which have no other Western attestation. But it is a characteristic of all witnesses to the Western text to present unique readings ; these need not therefore be Marcion's own." [Robert Smith Wilson Marcion p. 145] 

Harnack believes that these readings have no significance, since most of them are simply western readings, frequent in D the old Latin. (It may be added that many of Marcion's readings, as given by Harnack, later turn up in the Byzantine text). Frequently these western and Marcionite readings conform the text of Luke to Matthew and Mark. Knox points out that this does not necessarily mean that Marcion got his textual tradition from Rome; "western" merely means "unrevised local texts," and in his second edition Harnack admitted that Marcion may have obtained his text in the east. But this does not solve the problem whether the western and Marcionite text is in these passages more or less original than our neutral text. There are three possibilities, (a) that Marcion's recension is actually earlier and for that reason closer to the readings of Mark and Q, (b) that Marcion's Luke was already affected by the "wild western" tendency, and (c) that Tertullian and others unconsciously corrupted their evidence in a Western direction. Now, if the textual peculiarities are to be accounted for on Knox's theory, an ecclesiastical recension of Luke-Acts was made in the second century, but it was very soon affected by the text of Luke's older form, and Acts also underwent a great deal of textual change almost immediately. This is, of course, not impossible. On the other hand, a simpler explanation is possible if Luke- Acts, substantially in its present form, was completed about the year 100. In both east and west, the text of Luke was much affected by Matthew and Mark, and it was manuscripts of type that Marcion utilized. Even if Marcion made use of a shorter recension of Luke, it may have undergone such textual change. [Anglican Theological Review Mercer p. 234]