Is the pickup on base or an offsite location? It makes a difference.
On base you have to have a current drivers license/id for each person entering the base, current insurance and registration for the vehicle you are driving. This is to get thru the guard post. The GL site just wants to see the paid invoice.
Off base you usually just need a copy of the paid invoice.
That being said, I made a pickup at an Army base. I was driving a Deuce for a flat tow home. The guards just waved me thru the gate.
Another time at an AFB I brought a pickup with a goose neck. It took 15 minutes to be checked out just to get thru the gate.
Once you get to the GL location you have to wait your turn and they just want you out of there. Not much paperwork involved.
As said before, call the GL site manager before hand and ask about any special instructions.
Warthog
P.S. Welcome to the "OD Fever" club