As requested, closer pics of Marvin, thought to be 16 Ad Wksp. Also the faded Christmas tree and ERN 5434. Of note, the Kangaroo faces left on both stencils, so on the left side of the vehicle it is hopping forward, but on the right is going backwards.
On both sides, the paint used for the ERN, kangaroo and "Army" have faded badly. Was this paint red, blaze orange, or Day-Glo orange?