I have found an MI for both Margaret and Thomas.
Margaret's reads:
Sacred to the memory of Margaret McNay died 18.1.1921. Agnes Catherine McNay died 16.2.1931
And next to them Thomas's reads:
Dr McNay, J.P. In loving memory of my dear husband Thomas McNay died at Dalveen, Larkhall 22.1.1943. Also his wife Agnes McNay died 27.5.1979
Hope this helps
PP