I've tested all of my pots obtained from the local here and they have no lead in the GC spectrum. I found many organics which most likely are proteins and substances with benzene rings and fats from the hot water brewed in the pot. Hope no shoe polish
The pots from YLL sourcing and 5000friend were already gone, I have no chance to test them, but the one from YLL could be 'thight' to pass the heavy metal test, especially if the test is done by brewing in acidic liquid (like you idea before) as it has a visible piece of metal buried in it.
One interesting info, I heard from one other member here (can't write the username without permission), the pots (don't know whether they're new or vintage pots) from 5000friend also pass the commercial lead test kit