Sentimental gift for a couple that has everything?

My dad is getting married to his partner that he’s been with for 10 years. They are both late sixties. They have a home together and obviously aren’t in need of glassware or pots and pans. My dad is a really sentimental guy and would love something thoughtful. I thought about a commissioned painting but they have a ton of art from my grandmother who was an artist and a couple other custom paintings already. My step mom also quilts so that feels out too.

Any ideas for something custom and sentimental that isn’t a painting or quilt??

EDIT: thank you all so much for so many great suggestions! Just FYI: they aren’t planning to have a photographer for the wedding. It’s a small (well, 100 people so not that small!) back yard affair.