I hadn't noticed until you pointed it out. A "Carryall" is broadly defined a "vehicle in which two seats face each other" and I find a golf cart like vehicle called that for sale. More searching revealed a bit of an autobiography in which the writer says he and his brother bought a carry-all and he defines it as "and a bright yellow, van-like "carry-all" (bought for fifty dollars at Army Suplus in Phoenix).."
fac-staff.seattleu.edu/.../postcolonialautobiography.pdf
So I assume it's a sort of van rather than a truck.