Do you have a screenshot of its original condition? I have been working the past few days on fixing a lot of the gym's on the server and the more information on each gym I have the better.
Maybe you can go into single player and build it so that you can take screenshots showing how it used to be setup before it was destroyed?
I can actually explain it quite simply. The area around the gym leader was a carpet in the shape of a pokeball, with 2 statues in front. There is steps leading up to it.
I have gone ahead and rebuilt the Earth Gym, Its not the best but it is better than it was before I started. Enjoy... and thanks for the suggestion.