:Thanks for the info Michael. I did not see Smart's article. I based my edit on three books I had on hand, the two I cited, plus Elizabeth Forbes article in New Grove Opera, all of which agreed and are considerably more recent than Bord. (As you know, the other Wikis are not acceptable as reliable sources.)  My inclination is to rely on Smart's 2001 New Grove article. Since she cites Bord's book, she must be aware of the document quoted by Bord. Documents such as these can sometimes have errors. I saw that Smart published an article about Stoltz in 1994, which may possibly have more details. She also cites an article in Italian by Appolonia, which may address this issue. Right now I would be OK with using any one of the three dates and mentioning the disagreement in the other sources in a footnote.