So this French government database has documentation on some recipients of the Legion of Honour, but according to this page it might only contain recipients who died before 1977, which I'm assuming isn't the case for your uncle. However, also on this page it says "if this person was decorated after the 19th century and you don't find them in the database, you can request information from Mrs Christel Guezello by email at gestion.mm@legiondhonneur.fr." Include the first name, last name, birth and death dates.

Mods - I know this may not fit the subreddit rules, so feel free to delete, as I'll PM OP this information directly.