Older PCI slabs
I have several PCI slabs with the 10 digit ID number. In my amateur eyes they are graded pretty well (in any case, not valuable enough coins to justify regrading). However, they all seem to have toned more than I would have expected. I'm a little concerned that either they added an agent to hasten toning or there is PVC residue that could do harm.
I have added some pictures and am curious if anyone has an opinion whether the toning is fine as-is or if I should crack them out and give them a rinse. FYI, these are the more obvious ones but the others also toned to a lesser degree.
Thanks for your thoughts.