l bought these for a client from an auction house in Kent, England.
l have always tried to buy beautiful/unusual things as and when l have seen them because it's impossible to create interesting spaces by only sourcing from standard retailers. Good luck with your hunting!

is this char strong enough to hold people? i doubt

Solid cast iron. Of course it does it's job properly........ assuming we are talking about people of normal weight for their height and age. l wouldn't be specifying products that are not suitable for purpose........ apart from my clients the Professional Indemnity Insurers wouldn't like it either!