You can ring there will be a number somewhere in the AIP.
Its not usually a problem asking the agency you are already talking to unless they are busy.
But personally I would have asked plymouth mil on 124.150 on box 2.
Even if it is hot they know whats going on and if they can they will clear you through anyway.
All my dealings with Plymouth Mil I have been extremely impressed on not only there attitude in allowing access to the danger areas but also there motivation in putting extra work in to help you out. Its definately we won't let you through if we really can't but if there is a way, you can do it.
I am sure some have had other not so good experences with them.
But I have always found them a nice bunch and a credit to thier service.