It is always useful to analyze an object by comparing it to spoons known to have belonged to Napoleon, so thank you for sharing it with us. I haven’t seen the online listing, so don’t know what claims are being made, or by whom. But on the face of it, I believe this spoon is a fake for the following reasons:
-The shape of the bowl is not Empire style. It should be more pointed, and the bowl should be shorter and more narrow. Napoleon always had the most contemporary and stylish objects of his time. This looks like a plain, ordinary 18th C spoon that has been gussied up to pretend like something it isn’t.
-The engraving is crude, and not what one would expect for the Imperial household.
-Double engraving is unusual. I’ve never seen both back and front personalizations.
-The coat of arms is incomplete.
-The marks appear fake: depth of strike, relative size. The maker’s mark is incomplete. Silversmiths to the Imperial household would mark objects very carefully as a point of prestige. Napoleon I’s flatware makers were Naudin, Biennais, and Lorillon. This partial mark doesn’t resemble any of their marks.
-Well-documented flatware belonging to Napoleon exists in various museum collections: Louvre (Puiforcat collection), Montreal Museum of Fine Arts (Weider and Joyal collections), and the Royal Scottish Museum. These collections are all published, and objects in them can be compared to this spoon. See an example of two coffee spoons herehttps://www.nms.ac.uk/explore-our-colle ... _id=365324
For a nice overview of Napoleon’s known flatware see the catalogue for a 2003-2004 exhibit at the Louvre:
Dion-Tenenbaum, Anne. L’orfèvre de Napoléon: Martin-Guillaume Biennais. Paris, Editions de la Réunion des musées nationaux, 2003.
In summary, I wouldn’t want to find this spoon under my Christmas tree. Happy holidays to all!