Roger: Regarding photography, not sure. Guess I should have checked. I hope they don't sic any zombies on me. Most everyone on the tour was taking pictures and I was pretty conspicuous about mine. I am assuming my guide would have said something. There's probably a stricture regarding commercial photography so it would be best to check with the staff at the cemetery.
Also, David gives group and individual tours. You can contact him at dpetry@gmail to arrange a similar jaunt!
Tenoreleven: Funny you should mention dance - that's exactly what it looked like and what drew my attention. I even shot some video of their movements. I'm happy that the image brought that to mind!