The AlMahdyoon website has this post on there, which translates as…

Al Islam is the fruit of the divine religions on the earth and Muhammad is Jesus, Moses, Abraham (pbut) and the Qur’an is the Torah, the Gospel and the scripture of Abraham.

Allah said: (He has established for you in the religion what He bequeathed Noah and that which We have revealed to you, to Abraham, to Moses, to Jesus – establish the religion and do not differ in it (Shura: 13)

الإسلام ثمرة الأديان الإلهية في الأرض ومحمد هو عيسى وموسى وإبراهيم (ع) والقرآن هو التوراة والإنجيل وصحف إبراهيم

قال تعالى (شَرَعَ لَكُمْ مِنَ الدِّينِ مَا وَصَّى بِهِ نُوحاً وَالَّذِي أَوْحَيْنَا إِلَيْكَ وَمَا وَصَّيْنَا بِهِ إِبْرَاهِيمَ وَمُوسَى وَعِيسَى أَنْ أَقِيمُوا الدِّينَ وَلا تَتَفَرَّقُوا فِيه ) الشورى:13

Further, Syed Ahmed Al Hasan as references many modern and ancient books and encourages us to find proofs of the dawah in them including references to Imam Mahdi, hence, searching for relevant references is very useful for someone who is looking to support their understanding of this Call and to propagate it.

However, care should be taken not to focus to be diverted from the proofs given by the Syed as and the Najaf Office, since not everything that calls to the truth is 100% reliable in its every aspect.