That Brinks truck is built on a 1969 International Scout 800A. Quite a departure from the behemoths they usually wield. The only thing that could be smaller and yet still viable would be a Jeep, but that would be just plain silly. But wait...
In this Dennis Brearley photo, that's a J. Tom Moore & Sons built armored car on a Jeep CJ-5, owned by the Armored Banking Service of Lynn, Massachusetts. That arrow in the window is pointing to a bullet hole received on July 26, 1966 during a daring—and sucessful—robbery.
The Boston area was having a spate of armored car robberies—this being the fourth since May 26, all believed to be committed by the same gang. In this case, two Armored Banking Service guards were delivering money to the Veteran's Administration Hospital in Jamaica Plain and had just exited their vehicle when a blue panel truck pulled up in back of them. Three men wearing ski masks jumped out and began shooting machineguns, hitting both guards from behind—one guard in the left thigh and the other in the lower back. Other rounds sprayed the front of the hospital, shattering windows and hitting the switchboard room and an employee's lounge, but no one else was injured. The bandits grabbed the money bags that the guards had dropped and fled the scene in the panel truck, which was found abandoned about a mile away. Because this last holdup occurred on government property, the FBI was called in in the case. It was the second hit on the Armored Banking Service.
So the Armored Banking Service seems to beat Brinks in the diminutive dough-delivery device dare. But wait - there's more! Eleven years earlier...
This Tom Baffer photo for the New York Daily News show burlesque dancer Evelyn West being escorted out of a Brinks Willys surplus M38-based armored car. The picture had as the original caption:
Photo shows Evelyn (Treasure Chest) West arriving at the Fifth Ave. Jewelers Exchange in an armored car.  She has on $1,000,000 in jewelry which she will wear during her performance at the Adams Theatre in Newark.  Armed Guard is Jim Donahue.Evelyn "$50,000 Treasure Chest" West (she insured her breasts for $50,000 through Lloyd's of London), aka The Hubba-Hubba Girl,was one for stunts—this one thought up by her agent.
Oh, and the M38 has a one-inch shorter wheelbase than the CJ-5, so Brinks wins.