Here are a few passages that I identify as being Marcionite in nature. These seem to suggest either that the orthodox letters are derived from Marcoin's or that the original letters are more aligned with Marcionism than believed.
2 Cor 3:
7 But if the ministry of death, in letters engraved on stones, came with glory, so that the sons of Israel could not look intently at the face of Moses because of the glory of his face, fading as it was, 8 how will the ministry of the Spirit fail to be even more with glory? 9 For if the ministry of condemnation has glory, much more does the ministry of righteousness abound in glory. 10 For indeed what had glory, in this case has no glory because of the glory that surpasses it. 11 For if that which fades away was with glory, much more that which remains is in glory.
12 Therefore having such a hope, we use great boldness in our speech, 13 and are not like Moses, who used to put a veil over his face so that the sons of Israel would not look intently at the end of what was fading away. 14 But their minds were hardened; for until this very day at the reading of the old covenant the same veil remains unlifted, because it is removed in Christ. 15 But to this day whenever Moses is read, a veil lies over their heart; 16 but whenever a person turns to the Lord, the veil is taken away. 17 Now the Lord is the Spirit, and where the Spirit of the Lord is, there is liberty. 18 But we all, with unveiled face, beholding as in a mirror the glory of the Lord, are being transformed into the same image from glory to glory, just as from the Lord, the Spirit.
Wow this is harsh. The "ministry of death"! Here "the Lord" is the Spirit. Certainly no "son of David". Moses essentially condemns the Jews.
Romans 10:
1 Brethren, my heart’s desire and my prayer to God for them is for their salvation. 2 For I testify about them that they have a zeal for God, but not in accordance with knowledge. 3 For not knowing about God’s righteousness and seeking to establish their own, they did not subject themselves to the righteousness of God. 4 For Christ is the end of the law for righteousness to everyone who believes.
The Jews don't know God.
Romans 10:
11 For the Scripture says, “Whoever believes in Him will not be disappointed.” 12 For there is no distinction between Jew and Greek; for the same Lord is Lord of all, abounding in riches for all who call on Him; 13 for “Whoever will call on the name of the Lord will be saved.”
14 How then will they call on Him in whom they have not believed? How will they believe in Him whom they have not heard? And how will they hear without a preacher? 15 How will they preach unless they are sent? Just as it is written, “How beautiful are the feet of those who bring good news of good things!”
16 However, they did not all heed the good news; for Isaiah says, “Lord, who has believed our report?” 17 So faith comes from hearing, and hearing by the word of Christ.
18 But I say, surely they have never heard, have they? Indeed they have;
“Their voice has gone out into all the earth,
And their words to the ends of the world.”
19 But I say, surely Israel did not know, did they? First Moses says,
“I will make you jealous by that which is not a nation,
By a nation without understanding will I anger you.”
20 And Isaiah is very bold and says,
“I was found by those who did not seek Me,
I became manifest to those who did not ask for Me.”
21 But as for Israel He says, “All the day long I have stretched out My hands to a disobedient and obstinate people.”
The above may not have been present in Marcion's text, but the evidence, as usual, is not easily deciphered. But interestingly, this makes the claim that the Jews have never known God, and uses the Jewish scriptures to prove it. This sounds like a Marcionite thing to do to me. This one may be questionable.
Philemon 2:
1 Therefore if there is any encouragement in Christ, if there is any consolation of love, if there is any fellowship of the Spirit, if any affection and compassion, 2 make my joy complete by being of the same mind, maintaining the same love, united in spirit, intent on one purpose. 3 Do nothing from selfishness or empty conceit, but with humility of mind regard one another as more important than yourselves; 4 do not merely look out for your own personal interests, but also for the interests of others. 5 Have this attitude in yourselves which was also in Christ Jesus, 6 who, although He existed in the form of God, did not regard equality with God a thing to be grasped, 7 but emptied Himself, taking the form of a bond-servant, and being made in the likeness of a human being. 8 Being found in appearance as a man, He humbled Himself by becoming obedient to the point of death, even death on a cross. 9 For this reason also, God highly exalted Him, and bestowed on Him the name which is above every name, 10 so that at the name of Jesus every knee will bow, of those who are in heaven and on earth and under the earth, 11 and that every tongue will confess that Jesus Christ is Lord, to the glory of God the Father.
Note from BeDuhn:
2.5–8 Tertullian, Marc. 5.20.3–5; Eznik, De Deo 375 (vv. 5, 7; =Harnack vv.
6–8 only). In v. 7, Tertullian appears to attest the reading “of a human
being (anthrōpou)” instead of “of human beings (anthrōpōn),” in agreement
with Gk ms P46, the Palestinian Syriac and Coptic versions, and
Origen. Eznik is paraphrastic: “another thing which they say is . . .
(that) the Good One . . . sent Jesus his own son to go and take the likeness
of a slave and to come into being in the form of a human being.”
Barnikol, Philipper 2, has argued that vv. 6–7 constitute an interpolation
introduced by Marcion into the text. The challenge to such a hypothesis
lies in explaining how such a sectarian addition worked its way
into every witness to the catholic text. To accept it, one must suppose
that the catholic textual tradition of Paul depends on the Apostolikon,
albeit with subsequent modifications.
Are there others? Are there reasons to read these passages in non-Marcionite ways?