No specific information, I'm afraid, but I have a photograph of the Kilmarnock Academy Cadet Corps Band, taken circa 1926. Don't know if David the younger was in the band but, if so, would be part of this group. My father, Hugh Knox, (born 1913) was also in the band and was around the same age as David, so may have known him. Sadly, my father is no longer with us so impossible to get further info. I'm attaching the photo in case it's of any interest.