Another version of the Abbas Pasha Manuscript?

I have been aware of the existence of another version of usul al-khayl, a.k.a the Abbas Pasha Manuscript for some time now. Hamad al-Jassir, in the introduction of his book usul al-khayl al-arabiyah al-khadithah (“Origins of the modern Arab horses”), wrote that he accessed a copy then with his friend Khair al-Din al-Zarkali (photo below) during a visit to his house in Beirut. Zarkali, a Syrian by birth, was a leading Arab intellectual, a diplomat, and Saudi Arabia’s envoy to League of Arab States. For a long time, I thought Zarkali’s manuscript was identical to the one Gulsun Sherif had inherited from her family, translated into English, and beautifully published with Judith Forbis, under the title The Abbas Pasha Manuscript: And Horses and Horsemen of Arabia and Egypt During the Time of Abbas Pasha, 1800-1860. Hamad al-Jassir’s Arabic book quoted liberally from the Abbas Pasha Manuscript. I never paid much attention to these, always preferring to go back to the original text. Recently, after rereading the original manuscript cover to cover, I realized that it did not include several accounts of strains that Hamad al-Jassir had attributed to the text of the Manuscript. One of these accounts is that of…