Have a call to Matt
He's more in studio/audio equipment maintenance and travel a lot for that but I know his base is in Normandy.
Maybe he can do the job on the syths, and probably happy to share stout https://www.mseaudio.eu/
You can ask to 16 music lab in Concoret (zip code 56430), maybe this is the closest to Normandie.
I will to help you to repair your minimoog but i am in Champagne (Reims 51100) it's a bit far i guess.