First of all, thank you so much for your support!
I'm happy to report I've solved the problem and I'm working like crazy on the jacket. Dawn, the gusset was the answer, I hope I will post more about this tomorrow, I took 2 or 3 pics with my phone and I will tell you about my progress.
Carolyn, I know yours is not exactly a Chanel jacket, but I wanted to mention your blog because it was you that decided me to make this jacket in another fabric than boucle!
Johanna, thanks a million for the drawing, I didn't have any drawing of an actual Chanel jacket except the one provided by Claire Shaeffer in her article.
LMH, thank you, I'd like to have that quotation. I have the article mentioned and another one, also by Claire Shaeffer, on making Chanel skirts.
Donna, I've never worked with silk boucle, believe me this knit wool stretches sooooo much. Thank you for giving me the link to your blog, I'll check out the entire archive, your tips seem so very helpful.
Until tomorrow, happy sewing everyone!