Hi Achim,
the second one is most likely the Nieuport of Adj. Alain Joussaud of N 75, who was shot down and captured by
Julius Buckler Jasta 17 on 12 May 1917. The photo is shown in an article/translation by Adam Wait and Al Zakrzewski about Bucklers book "Malaula" in the new OTF journal 4/2001.
Perhaps you have the "deutsche Ausgabe" at hand. Read the section on page 119 ff. "Der gefangene Papaine". The situation described by Buckler could also fit with the capture of Segent Papeil of Escadrille SPA 3... ???
VBR, Immo