Windows – Swap desktops between monitors (windows)

I want to be able to swap the desktop on monitor 1 with monitor 2.

"What is the best way to swap the part of the desktop which is visible on monitor 1 with the part of the desktop which is visible on monitor 2."

Windows 7 64 / nVidia.

Swap

Desktop-A -> Monitor-1
Desktop-B -> Monitor-2

-toggle-

Desktop-A -> Monitor-2
Desktop-B -> Monitor-1

I thought this was how virtual desktops worked! The solutions I've found using stretch the desktop across both monitors, or keeps each monitors desktops separate where you can't display Monitor-1/Desktop-A on Monitor-2.

Clone

Desktop-A -> Monitor-1
Desktop-A -> Monitor-2

-toggle-

Desktop-B -> Monitor-1
Desktop-B -> Monitor-2

I've looked at these
Actual Window Manager,
DisplayFusion,
VirtuaWin,
GiMeSpace,
NirCmd,
Dexpot,
Finestra,
mDesktop, and more… these can move one window at a time, and even specify which monitor a window should open on, but they have no way to swap whole desktops.

I might write an AHK to move the windows for me, but I'm sure there will be snags. Maybe someone has tackled this for various windows versions, and display dimensions, child windows…

Scenarios:
1. Move desktop in use to primary monitor.
2. The second monitor is temporarily unavailable. (tv)