Does anyone know how old this artwork is?

We have somewhere around ten of his paintings in our house, because he was my Grandpa's uncle. Ole Larsen was born in 1898 and died in 1984. We have a few of the serving trays that he painted on, as well as a horse picture that looks just like both of yours. We also have a poster-sized painting of the pictures from the dog breed book. It's really cool that pieces of his art are all over the place!