Smallpox - yes, November 1745. So all pretty close together indeed.
re: Schwedt cousin - did he get called "Königliche Hoheit" as well? Because see here for the departure note. But even if he did, I think the newspaper would have specified if he was meant, since their readers would have no way to know which one it was then. (Also, didn't Fritz rather dislike him at that point?) Plus, AW and Ferdinand are mentioned here as well, returning to Berlin from Potsdam, but no mention of Heinrich doing the same. That said, it's still possible that Fritz might have left him in Braunschweig to visit Charlotte on the way or something.
Re: From Pyrmont With Love? Waters, Spies, and Dogs
re: Schwedt cousin - did he get called "Königliche Hoheit" as well? Because see here for the departure note. But even if he did, I think the newspaper would have specified if he was meant, since their readers would have no way to know which one it was then. (Also, didn't Fritz rather dislike him at that point?) Plus, AW and Ferdinand are mentioned here as well, returning to Berlin from Potsdam, but no mention of Heinrich doing the same. That said, it's still possible that Fritz might have left him in Braunschweig to visit Charlotte on the way or something.