If its your first time there be prepared for a mental shutdown, as your mind can't understand their vast material. On Monday's and Tuesday's they open at 9:00am and shut down at 5:00pm. On Wednesday, Thrusday and Fridays they open at 9 and close at 9 so an extra 4 hours to research. I forgot what their hrs. are on Saturday. On rare occasions you will be the first one looking at the material since the Civil War.
The archives have many new people there also. So a new person telling someone who may not be familiar with the archives what to find could be an issue. I had a new person yesterday telling me that something did not exist and I had to explain to her that it did exist and showed her where to find it. What your contact may have told you was the truth it may not exist but I would not be willingly to bet on it unless I was there myself.
Computers and cameras are allowed in the research room at present but things like pens are not. I am finding mistakes that historians had been making for years with some of my research. It will be published in a few weeks and at that time I shall share it with Jim's site at the prison board.
If you are a poor person like me then consider driving a van and bring a sleeping bag and park at the Ronald Reagan airport about $10.00 per day and sleep in the van. Then catch the subway about $7.00 total to and from Regan to the Archives. Bathrooms are at the airport but good luck for showers. Anyway that is the cheap route. No costs for admission to the Archives while doing reserach.