Hi Philippe:
Thanks for the help. I also just had a look in the Windsock Nieuport Special vol.I of the color photos of the Nie.23, and that seat appears to be wooden.
Also just noticed that the Eduard Nie.21 kit has the wrong engine! It should have a 80hp LeRhone 9C instead of the 110 hp LeRhone like the Nie.17 that is in the kit.
Sheesh.
Will