Roger said before these are a ficticious item. The US Army M1040 and M1041 FAV never had a data plate installed beyond the Chenowth chassis tag welded to the rocker tube. These may have come about due to MVCC judging rules requiring a data plate, a previous owner with an otherwise perfectly restored FAV was dinged points for not having a data plate.
(Narrow/rigid minds within the mil vehicle collector hobby-remember the hate HMMWV owners went through in the early 2000s to 201Xs? Even on this board here, owners were punished for simply asking about how to insure their lawfully-owned property)