Over the Hill to the Poorhouse (the version I know is from Flatt and Scruggs, but the song goes way back)
Silver in the Stubble (did Cliff Haslam write it? his version is the one I know)
Old Age Pension Check (Roy Acuff)
Old and Gray and Only In the Way (Charlie Poole) (particularly enjoy singing "so let us cheer them on, for they won't be with us long")
and so on!