It seems that none of these victories can be verified.
But about Dufayet (page 281) in The Russian Military Air Fleet in World War 1:
French S/Lt; pilot; ESC.N.581; on 13 November 1917 he was decorated with the Order of St. George 4th Class for a mission on 2 August 1917 when he attacked two enemy aircraft and managed to destroy one of them east northeast of Losich. He was badly wounded in the combat.
Note: He had received the French Military Cross 2nd and 1st Class in July 1916 for selfless actions in Verdun operations.
"Kennscht mi noch? "