Braheen Volume 5 does not continue the first topic (out of 300) started in Volume 4. Rather, it is dominated by the rest of the publications of Mirza Ghulam Ahmad during that time period (circa 1905). Some excerpts:
It is not my claim that I am the Mahdi that fulfils the ahadith "out of the progeny of Fatima" and "of my people" etc. On the contrary, my claim is to be the Promised Messiah – and there is no saying of any scholar of Hadith about the Promised Messiah that he will be of the children of Fatima.
However, just as all scholars of hadith say, I also concur: that all ahadith about the Promised Mahdi are injured and doubtful and not even one of them is correct. And the fabrication that has gone into these ahadith – no other hadith was subject to such fabrication. During the reign of the Abbasid Khalifas, the Khalifas wanted very much to delcare themselves the Promised Mahdi. This is the reason why, in some Ahadith, they declare the Mahdi from Bani Abbas, and in others, declared him to be from Bani Fatima. And some ahadith even say that "he is a man from my Ummah". In fact, all those Ahadith are not at all reliable. This is not only my word, but the great scholars of the Sunni persuasion have been saying this all along.
And compared to all these, the hadith in ibn Maja is very correct : "there is no Mahdi but Jesus" – that is, there is no Mahdi and only Jesus is the Mahdi (Guided One) and will come._ (translator-this latter part is a misquote of the hadith, see elsewhere)_
(Appendix Braheen Ahmadiyya Volume 5, Roohani Khazain Vol 21, p.356)