Thanks GUEST, that clip is brilliant, of course, though he's got it "upside down" and playing the strings "below the buttons", whereas I'm proposing to keep the bass strings near me, for the stronger bass end thumb strum.
Perhaps a bit more experimenting is called for before I get set in my ways. Though I don't want to keep moving the chords around too much (those springs sure do move fast when you're not looking....)