Thank you for your very informative reply.
I cannot find any similar event, so hope this case is an unusual decision. Otherwise, does this mean that a U.S. internal flight, which does not go through Customs, is prohibited too, or can it be safely packed in someway?
I would still like to buy the item to put on the dash of a date-related classic rally car but cannot see a way to do so.
Any advice greatly appreciated.