There are situations where equipment has to be modified and the NEC knows this. An old lamp that has to be rewired is a good example. In those cases your liability can be limited by having an electrical inspector sign off of the work. Off course this is crazy to do on every plasma you sell but if you are concerned about it that's the path of least resistance. I have had it written right into my liability policy that I sometimes change plugs ends, outlets and switches even though I'm not a licensed electrician. Won't protect me from getting hauled into court but it should go a long way towards forcing the insurance company to pay a claim. When I did this the only reply that came back from the underwriter was a notation saying that I would not be making any connections into a load panel, everything else was fair game.