I wish I had found a complete picture of this truck from Camden, NJ, but it appears we’ll have to make due with a partial image. I think that’s supposed to be a wooden typewriter on top. Here’s the original link.
“Sitting on the wall are Mr. Robison’s nephews and niece, Tony, Annamarie and Joe Di Paola Jr. In the background, parked on the Haddon Avenue side of 964 Pine Street is the Willys truck belonging to Robison’s Typewriter and Cash Register Repair.”