The originals are no doubt lost to history, but I am curious as to what the oldest iteration of monks' copying the stories down on paper is to survive to the present.
Two derive from a common lost ancestor: these are:
Amsterdam 73, 2nd quarter of the 9th century, written at Fleury (=A)
Paris lat. 5056, 11-12th century, written at Moissac (=Q)
So 9th century seems to be right. The remaining four derive from another now lost ms:
Paris lat. 5763, 1st quarter of the 9th century, French, later at Fleury (=B)
Vatican lat. 3864, 3rd quarter of the 9th century, written at Corbie (=M)
Florence, Laur. Ashb. 33, 10th century, possibly French (=S)
British Library Additional 10084, 11-12th century, probably from Gembloux (=L)
Source: L.D.Reynolds, Texts and Transmissions, pp.35-6, written by Michael Winterbottom.