I am currently reading the final pages in Part II of Don Quixote and soon will have a series of remarks to make about it in relation to The Manuscript Found in Saragossa.  Having finally completed Cervantes' epic novel (and a very modern, meta-fictional one to my mind), I have found it to be the true mother-load of influence (far exceeding the influence of The Arabian Nights), the primal fount of inspiration and material for Potocki's own work.  Cervantes is indeed like the proud grandfather of The Manuscript Found in Saragossa. Potocki has modernized, updated, Cervantes.  As with some movie re-makes, much material may be greatly altered, but the thematic bones remain the same.