Great picture, Robert! I've had that one a while (collecting images of F-1A trailers, and never noticed the name :blush:), but always assumed it was Italy. No white star either???
Seems that ASSRON is/was used an acronym for AIR SERVICE SUPPORT SQUADRON - ARMY. This sounds very much like a post war thing when acronyms became popular, although it does fit with the wartime scenario of the air Forces being part of the Army (USAAF) rather than a separate entity after 1947 (as in USAF).
Perhaps it's best to regard it simply as a great vehicle name :-D