Liberty Blue Staffordshire Ironstone Vintage Plate: 44,500 ppm lead.
The amount of lead that is considered toxic in a newly manufactured item intended for use by children is 90 ppm or higher. Vintage china is not regulated for total Lead content (as detectable with an XRF instrument.)
Please note: I am not saying “this particular plate will poison the people using it”! I am saying that there is no defensible reason for one of the most potent neurotoxins known to man to be in our cookware (especially at levels this high!) Period.