My grandfather got to know a family a France. We are fairly certain the photo below is that family. After the war my grandfather wrote them a letter and this is the reply he received (letter, envelopes and translation below).
St-Nicolas, June 17th,1920.
Dear Monsieur Robert,
I have received your letter which, I must say, thoroughly surprised me. I genuinely thought you had forgotten about me, but I now see I was mistaken in thinking so. You tell me your ancestors were in France for 150 years. Which part? Could you potentially tell me?
Little Jean remembers you very well, as well as all the good moments ever spent with you. He asks that I share with you his most sincere friendship*
I would love to come to see you, as well as your parents, and your cousin, but it’s quite a long way away, though I still have hope to see you again one day. Could you send me your photograph, alongside one of your parents?
Kiss them for me, will you, as well as Monsieur Joé, as he is definitely not being forgotten either. And you, dear friend, receive the dear kisses of a little French lady who won’t forget you.
Here is my address:
74 Grande Rue 74
Meurthe et Moselle
*French expression for good wishes