You are absolutely right that: "... I must say that TODAY, the Torah and Injeel are definitely not the same books that they used to be at the time of the Prophet (pbuh). And there is a subtle reference to this prophesy to be found in the Qur’an. So if you say that TODAY these books are not the same, I can agree with you there."
The Original OT & NT, and even those of Prophet Muhammad's (S) times, certainly do not exist today.
A precious article from a noted Christian denomination reconfirms the fact very strongly, rather harshly.
An Un-edited Note from the French Episcopal Church:
"They claim that the Bible being the Word of God has not changed. They should answer which Bible has not changed. Hebrew Bible, Greek Bible, Latin Bible, English Bible, Jewish Bible, Catholics’ Bible, Protestants’ Bible, Mormon Bible, Watchtower Bible, Eastern Orthodox Church's Bible - which Bible are they talking about? All these Bibles individually and collectively have been changed and are still being changed. Jews call the Old Testament, the Hebrew Bible or TANAK. But their Bible has 24 books and some books have been divided into two parts to make up for a total of 39 books. Protestants also have 39 books but in a different order. The same Old Testament of Catholics has 46 books, while Eastern Orthodox Christians have 51 books in their Old Testament. Jewish version of the Bible is based on the Hebrew Masoretic text while Christians generally use the Greek (Septuagint) and Latin (Vulgate) versions as the basis of their Old Testaments. Each group also has variations in the texts of their books as well as in the number of verses.
The New Testament is accepted by Christians only. It has 27 books: Four Gospels and then other books and letters named after various apostles. But Catholics add some verses in the Gospels that are not accepted by the Protestants. The Catholics as well as the Eastern Orthodox Christians acknowledge some books that are not accepted by the Protestants.
As far as the ancient manuscripts of the Bible are concerned, it is known to the Biblical scholars that most of the manuscripts came from the fourth century CE down. These ancient manuscripts are essentially partial and their texts differ from one another very significantly.
M. M. Parvis in the Interpreter's Dictionary of the Bible (vol. 4, pp. 594-595) says, 'The New Testament is now known to exist, in whole or in part, in nearly five thousand Greek manuscripts alone. Every one of these handwritten copies differs from the other one. It has been estimated that these manuscripts and quotations differ among themselves between 150,000 and 250,000 times. The actual figure is, perhaps, much higher. A study of 150 Greek manuscripts of the Gospel of Luke has revealed more than 30,000 different readings. It is safe to say that there is not one sentence in the New Testament in which the manuscripts' tradition is wholly uniform.'
Anyone can get hold of the Good News Bible and can see for oneself that in the 1300 pages of this modern English version, there are almost as many footnotes pointing to phrases, sentences and passages that are omitted from or added to various ancient manuscripts or versions. Many of these alterations are not unintentional scribal errors such as are expected in handwritten copies of a book. A careful study of ancient texts has convinced scholars that the variations found in them were very often intentional tampering with the texts. This tampering is still going on for various political, theological or ideological reasons. Under pressure of the Jewish organizations, many churches in America and Europe have begun rephrasing Jesus' criticism of the Jews in the Gospels. Feminists groups are urging the use of unisex language in the new versions. Homosexual groups have their own versions. All these changes are taking place before our own eyes. Of course, people can believe whatever they may wish."