Stu,
I don't have one I want to sell, as you are aware, these are hard to come by. I had to put one in the oven to make it fit, the Givi I have, the mount hardware I searched the world over and had to get a forum member (from another forum) in France to assist in getting the kit to the states for me.
The guy did not ask for any money until I received the kit from him, great guy. As you say I don't know that the two shields are interchangeable.