It came from Grumman directly.
The postal vehicles are Right hand drive. Also the postal LLVs don't have windows in the cargo area. (Security)
The Post Office and Grumman had a sort of falling out and Grumman took what they could from the contract to make money selling Urban Delivery vehicles. They kissed and made up though.
The Post Office does have the largest fleet of alternative fuel vehicles in the world right now. Including Electrics and CNGVs, etc.
We have 2 of the CNG trucks where I work and a contract with the gas company down the road to fuel them.
Happy Bidding,
S.