I'm actually in Dijon, France, due to dramatic events here...
In the train, I've read a book of my collection: "350th Fighter Squadron 1941-2006" - Colonel Aviateur J. JACOBS. The book contains a photo of the Spitfire MK II MN-A and gives the name of the pilot:
Wing Commander Désiré GUILLAUME; first Belgian CO of the 350th Sqn, from 20/03/42 until 20/12/42.
I'm glad to have found this information...