Firstly, Merry Christmass to everyone
As promised, a few pictures
The guitar left by a GI in the farm during the summer or the fall of 1944

On the back, an engraved name with a small flower

The name look to be "Ph. Cohemant" or "Ph. Eohemant"
And finally, the autographed banknote, signed by the officers of the Engineer Unit

I don't have the complete name of the Commanding Officer, but I know for sure, it's first name was Matthew, and from what is readable on the banknote, (on the upper left part) his last name looks to start by "Ray" or "Kay".
I know he survived the war as my "grand-grand-mother" stayed in contact with him until around the 90's.
Visibly, his wife was speaking/writing a bit in french and various letters were exchanged during the years. Unfortunatly, I don't have these letters.
I don't know if there is other usable information on the banknote ?
I don't have any official information on this unit, and of course I will be very interested to discover where they goes after their stay in the farm and the complete story of the unit accross the war.
If someone has an idea of where it could be possible to find information ? Any help would be much appreciated.
Regards
Loïc