As I said, I am not sure there is a good method to determine the extent of lead absorption and risk, but there might be, and the tests performed by CEH (Center for Environmental Health) were aimed at just that. Their claim was that lead leaches from brass mouthpieces exposed to saliva even when they are plated. I think they had articles on their results available, but I recall they were not detailed. They are not in the business of science and publishing research, they are a consumer protection non-profit. I don't think they tried to publish their results in a peer-reviewed journal -- the results seem to be embargoed while their litigation was/is in progress. One thing about publishing is peer-reviewed journals is that it takes funding and recognized academic qualifications, and this is a very specialized area where there may not be enough academic interest due to its impact on a small number of people. This is just one effort of theirs in a series of many unrelated efforts. What would they have to gain? They are not fear-mongering for fun; they are activists trying to protect others from environmental hazards. Kids play brass mouthpieces in school. But yes, in principle, the existence of a lawsuit does not make its claim credible. Also, peer review can help, but it is far from perfect and after years of experience publishing research, I find peer review does little to prevent incorrect published work. In cases where work can be reproduced, publication provides the results and methods and allows others to attempt to do so. I would love to see such work published by qualified experts, but I also recognize it is a question which is very hard to answer quantitatively.
In my posts #8 and #10 the results you requested are clear. There is a relatively high lead concentration on the surface of this bare brass mouthpiece. I can get it measured accurately at a lab near me if I need to, but for me it's enough. I am a physicist, not working on materials, and not a biologist or medical researcher, and am not interested in an extensive investigation into an area (risk of actual absorption) where I don't think there is a definitive answer due to the many variables. In my personal judgement, the risk of lead exposure and absorption is high in this situation. I have not played this mouthpiece since I tested it and I do not plan to play it until it is plated. If the plating begins to wear, I will get it replated. Or, I might duplicate it in a non-toxic material. I would be interested in suggestions on that. This is a great mouthpiece for me. I will probably get this mouthpiece silver, then gold-plated over that, but I have also switched to hard rubber until then.