I then had a light bulb moment. Why not use this kit to test trims like buttons, zippers, and metal trims. When I buy buttons, I have no idea where they come from because I buy them from a jobber. All I receive is a bag of buttons. Lead testing at a certified lab can be expensive, not to mention the extreme backlog that is occurring right now. Lead tests start at $35 and can vary by lab. (BTW, getting pricing information is extremely difficult and requires lots of phone calling). Why not use one of these kits?
Consumer Reports states that the kits are only useful for detecting high concentrations of surface lead. False positives/negatives are a real possibility. The CPSC says there are no reliable home lead test kits. The CPSC is in conflict with Consumer Reports and it is difficult to know who to believe. CR actually used the test kits to check toys in actual use by children. Any toys that indicated high lead levels were sent for further testing. The results were surprising as they found some toys not on any recall list with extremely high levels.
While no one should rely solely on the home test lead kits for definitive information, I think it could at least give an indication of a problem. I may buy a kit despite what the CPSC says.
Here are some links to testing labs that require further research. At this point, I can't recommend one over the other. These labs can test for lead as well as most textile testing.
STR - lab highlighted by an ABC news article, also does textile testing
Bureau Veritas - formerly Acts Testing