Hi Ian!
First of all, I love your story, and I think most of us romantic souls here on the forum do so, too.
It may be disappointing for you, but I doubt that anyone on the forum or elsewhere will be able to tell you the story behind this or any other song. (Except maybe for Sophie herself, but she does not like to talk about her songs. You can read on Sophie-Zelmani.com (where she has given an interview) that she describes her songs as her very secrets. So at least we can think that many - if not all - of her songs are very private and autobiographical.
But does it really matter for you what the story behind this song is and for whom it was written. As you have told you have got your own imaginations and pictures and your own very private story behind this song.
And isn´t that what a great piece of art is all about? Seeing a picture or listening to a great song and then having your own very private feelings and thoughts, that are maybe impossible to form into words or share with other people?
Markus