In Europe, one of the leaders in the pattern industry is Marfy (similar to McCalls, Simplicity, and Vogue in the US) and their designs are the closest thing we can get to couture. Marfy published a few patterns on their website that are free to download including Marfy 1756.
Marfy 1756 pattern is for a tight fitting jacket with a nice shirt collar and closes with hooks. It has four pockets with flaps and buttons and it is a good pattern to sew a Chanel inspired jacket with a nice boucle fabric.
This pattern was published in Marfy.it website and is available in European sizes 42-58 (US sizes 14-28)
Below is an example of a jacket made using Marfy 1756. This jacket was sewn with a nice novelty denim fabric. I love how she incorporated the fabric salvages on the neck, sleeves, and hem.
Picture from Couture et Tricot
I made a Channel Style Jacket using a different pattern, but I love this one and is in my list. I hope you like it!