PM6 with a gaggle of RMEYs at the head end, you will notice the lead RMEY is the first wagon built. It originally had curtain sides and roof, obviously this didn't work too well. I am sure the Desert wind ripped it to shreds really quick.
We are looking at a version for Barcoola, I think the base should be fairly easy, the roof will be the hard bit. I am looking at a pass coach clear plasic roof, and then paint on the cage.
Anyway food for thought.