Hi, Ladies, thank you for your contribution to this post, I take it as my learning opportunity
some updates: I began the returning process, ebay told me that as the scarf is a cross-border purchase, they don't want me to return it to France at this moment for blablabla reasons, so they found me an authentication service (photo authenticated), and go from there. I am still waiting for this second opinion.
I will update my post later
Please do post the names of the scarf authentication services and your experiences - perhaps the eBay seller thread would be a good place for future reference
I am always asked for outside paid services since I know a freebie authentication here carries no weight at eBay