This is a very short description. We did this beautiful ascent this August and I think it requires a few more words. Would you mind updating it? Or, simply allow me to do that.
In the name you mention Couloir du Saix Rouquin. Is that the same as Couloir du Serrauquin? Sounds similar. Also, I have not noticed red chamois marks. That's strange and I'm sure I was not that tired to overlook them ;)