Hi Paul,
I made a bad construction in the first place, so I re-made my wing stays in April. I ma now very happy with them. Here what I have done:
http://vouchtroadster.blogspot.se/20...1_archive.html
You can use the translation function directly on the blog (right menu). It is translated by Google, far from being perfect, but understandable...
... ah no, sorry, I forgot you were fluent in French
Good luck!