I was actually present during a 2257 inspection when the feds inspected Robert Hill Releasing as that is the sister company for White Tiger Releasing and located in the same building. In our case as well the cases of the people that I know were inspected the feds came with a very specific listing of both films and models. They were in no way interested in what room they were kept in, only that they were all together and easily accessed. They have a list of specific scenes and the certain models that appear in those scenes. It's (in my opinion) best to keep a copy of your records in your place of business with a spare copy in some type of a safe deposit box or something off property to protect them from fire or whatever. Kind of like a spare set of keys you keep elsewhere in case something happens to your everyday set. In 95% of the people that I know personally that were inspected, they were contacted a day or so before they were actually inspected to give them the chance to have everything in order for the feds when they arrived. In most cases if a model release is not in the files for whatever reason, they give you some time(from an hour, to a day it seems) to present that ID. Now I certainly can't say if they'll change that but your best bet I would think would be to have everything the way I explained above. If they come they are at least professional, but they have a very specific agenda.