Country Dance "Mum for that"

From John Johnson, "Twenty Four Country Dances" (1766); the PDF file is on IMSLP. The graphic below the score shows the strong -- and I think somewhat unusual -- frame of the sixth, Bb4-G5, along with one of the most clearly presented clausal vera endings I know. In Schenkerian terms, one would be obliged to pick the line down from Bb -- that strikes me as unmusical nonsense. In proto-background based linear terms, the sixth with a "stationary" G5 fits the tune beautifully.