"Earlier than Paul, what do you mean?"
Well, I reckon (i.e., assume) that Jewish Christians prior to Paul viewed the OT as prophesizing about Jesus. Offhand, I don't know how apparent that may be in the Letter of James, which I think is at least genuinely Jewish Christian if it's not by James (after a quick perusal it doesn't look like there is anything). But there are indications in later writings (such as the Clementine literature, which arguably incorporate earlier Jewish Christian material) that this was the case. For example:
And whether or not 1 Cor. 15:3-11 is (in whole or in part) an interpolation, as it stands it says:...James began to show, that whatsoever things the prophets say they have taken from the law, and what they have spoken is in accordance with the law. He also made some statements respecting the books of the Kings, in what way, and when, and by whom they were written, and how they ought to be used. And when he had discussed most fully concerning the law, and had, by a most clear exposition, brought into light whatever things are in it concerning Christ, he showed by most abundant proofs that Jesus is the Christ, and that in Him are fulfilled all the prophecies which related to His humble advent.
Recognitions of Clement 1.69
I also view Hegesippus as a reliable Jewish Christian source, given that what he says is in keeping with the Letter of James and Eusebius' comment that he used the Gospel of the Hebrews and "mentions other matters as taken from the unwritten tradition of the Jews" (EH 4.22), and James connects Jesus to Daniel in EH 2.23:...Christ died for our sins according to the Scriptures, that he was buried, that he was raised on the third day according to the Scriptures, and that he appeared to Cephas, and then to the Twelve ... Then he appeared to James, then to all the apostles ... Whether, then, it is I or they, this is what we preach, and this is what you believed.
And I think some of the Dead Sea Scrolls could have been written by proto-Jewish Christians and see James as a plausible candidate for being the Teacher of Righteousness (as Eisenman argues), about whom it is said in the Habakkuk Pesher (similar to James in the Recognitions of Clement and Hegesippus above):'Why do ye ask me concerning Jesus, the Son of Man? He himself sitteth in heaven at the right hand of the great Power, and is about to come upon the clouds of heaven.' And when many were fully convinced and gloried in the testimony of James, and said, ‘Hosanna to the Son of David,’ these same Scribes and Pharisees said again to one another, ‘We have done badly in supplying such testimony to Jesus. But let us go up and throw him down, in order that they may be afraid to believe him.’
...this concerns the Teacher of Righteousness, to whom God made known all the mysteries of the words of His servants the Prophets (col. 7).
They, the men of violence and the breakers of the Covenant, will not believe when they hear all that [is to happen to] the final generation from the Priest [in whose heart] God set [understanding] that he might interpret all the words of His servants the Prophets, through whom He foretold all that would happen to His people and [His land] (col. 2).