It would be still useful to consult the classic scholarship on the subject, in particular:
D. M. Lang, The Wisdom of Balahvar
idem, The  Balavariani
S. M. Stern and S. Walzer. Three Unknown Buddhist Stories in an Arabic Version. Univ. South Carolina Press, 1971
and of course Wallace Budge's work on the Amharic versions.

The Gui de Cambrai text for which Don has contributed an introduction is but one of the numerous
medieval vernacular versions, all of which derive from the earlier Byzantine (attr. to John Damascene),
Georgian, Arabic and other near eastern recensions.