A scan of much of the manuscript MS Leiden Or. 14.052 is available online. The main text of this manuscript is in a rather poor Arabic. The marginal and interlinear notes, however, are "in one or more West African languages", as yet unidentified. My best guess is that they're in Mandinka, based on the orthography's use of tanwīn and on the frequent word-initial a/i (suggestive of Mande's 3rd person subject pronouns), but I'm not sure; I haven't been able to decipher any phrases. Anyone else feel like having a look?