Susan,
Have you got any of Norman Iles' books on the 'Cock Robin' theme? You'd really enjoy them.

Henry VII and Richie 3's going at it was the END of a great divide, not the beginning. There are plenty of ballads with a distinct political theme in oral tradition, but they are overt enough. There are also many many political ballads that were double entendres but very few of these survived their own period, at least not in oral tradition. I've just spent a full day in the BL leafing through some and not one item is still remembered today.