Bring to mind:
A frind of mine plans and builds equipment for expos. When he went over to the US he brought all finished work and plans but was required to hire someone to assemble it :/
> All work performed in the exhibit area is under union jurisdiction and under safety jurisdiction. Show management and all exhibitors are expected to comply with the unions and with fire and safety requirements in effect.
> All work involved in the construction, touch-up painting, dismantling, and repair of all exhibits may fall under union jurisdiction. This work is to include wall coverings, floor coverings, pipe and drape, painting, hanging of signs and/or decorative materials from the ceiling, placement of all signs, and the erection of platforms used for exhibit purposes.
> Full-time employees of exhibiting companies may setup their own exhibits provided that one person can accomplish the task in less than one-half (1/2) hour without the use of tools.
So, was that restriction you mention based on US immigration restrictions, or on local venue restrictions?