Valentines letters

My great gran got given when she was younger a lovely valentines letter with a envelope where he drew the village on and wrote about his love for her. I really thought their could be something developed from it and I didn't want to do something basic of shooting the old letter against a new valentine days card, I wanted to show a bit more creativity so I want to go and move onto a documentary shoot of an old couple in my family (ie my nan and grandad) to show how they are still madly in love and how they have grown in love and age.