Is it reasonable to assume that a radio call to Lyons (in this case) will result in the necessary authorisation?
I would doubt it, unless you have good reason to need to go there (eg arriving to an airfield in the area).
It says "authorised aircraft" rather than "with ATC clearance". If it was as simple getting a clearance, then on NOTAM would be needed, as the class C & D airspace requires that anyway.