I'd like to go back and shoot it again, as well. I live closeby in Pennsauken, NJ. Seeing the number of people who were there for the public tours, however, I would say getting a private tour (15 people or more) is the way to do it.
The admission is $12 (parking nearby is $13) and there is season long tripod/monopod pass of $10. They are very accomodating and would most likely put together a photo tour of closed areas easily as they did for the Obscura Day group.
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Jim