The fragment (fols. 61-66 according to Durand's foliation) belongs between fols. 81 and 82 of Athos, Laura Gamma 67. These unique copies of some surviving photographs of the fragment were probably made in 1964-1965 on behalf of prof. Oliver Strunk, see his Essays on Music in the Byzantine World, New York 1977, ed. K. Levy, p. 232, note 8. The fragment renders stichera idiomela, among these several apocrypha, for Sunday of the Paralysed from the Pentekostarion section of the Sticherarion. Fols. 61v, 62r and 66v seem only preserved through sketches and notes made by Gastoue, Wellesz and Tillyard, see Strunk loc. cit.
See the description of the Durand fragments in the digital catalogue of the Chartres Library (The Chartres Fragment is Vol. II, no. V): Link