New member here! Just wanted to report that I took the plunge and purchased a Diane messenger bag in Châtaigner online two days ago. Was a bit trepidatious about the whole purchase since I'm essentially buying the bag without having seen it in person, but the photos and feedback here helped seal the deal for me!
For the record, this is my first luxury bag purchase. I wanted something extremely high-quality, of French or Italian origin, with a vegetable tanned leather that would patina over time. When I started out, I really liked the Celine 16 in black, Moynat Gabrielle in black or cannelle, and the Hermes Constance in brown. Then I came across the Diane and saw the messenger bag version and couldn't stop thinking about it - it was everything I liked about those other bags (design, unique clasp, quality leather) wrapped up in one bag.
Will update with the whole process/pictures once I receive it!