Here is an older article for those interested in Libyan archives and the history of Tripoli.
B. G. Martin, “Five Letters from the Tripoli Archives,” Journal of the Historical Society of Nigeria 2/3 (1962), 350–372.
“The five Arabic letters which form the basis of this article date from 1846 to 1870. They throw some light, but only on details, of the relations of Bornu with Tripoli during the second Ottoman period (1835-1911), under the reigns of Shaykhs ‘Umar bin Muhammad al-Amīn al-Kānimī and Shaykh ‘Abd al-Rahmān. The interest of these letters is at once historical and indicative, pointing to other discoveries of documents relevant to Nigerian history which will doubtless be made at Tripoli, and further, at the Başvekālet Arşivi in Istanbul, whence the bulk of the Tripoli archives of the late second Ottoman period was doubtless removed soon after the Italian conquest of Libya in 1911. Three of these five letters (Letters One, Two and Three) are internal Tripolitanian Government correspondence about Bornu affairs, while Letter Four is a copy of a diplomatic communication addressed by Mustafa Nūri Pāshā of Tripoli to Shehu (Shaykh) ‘Abd al-Rahmān of Bornu. Letter Five is an example of the Bornu diplomatic correspondence preserved at the Tripoli Archives, and was addressed by Shaykh ‘Umar to the Mushīr ‘Ali Ridā Pāshā of Tripoli.”