We also had some lead concerns regarding some coffee cups glazed in a cobalt blue color. We purchased some lead testing
swabs from a local Walmart that can be used to determine if lead is present in a surface that can be swabbed.
It turned out the coffee cups indeed did have lead present and should only be used for decorative purposes.
I would go out and buy some of the lead testing swabs and swab away on suspect surfaces to eliminate speculation and reduce concerns.