Ok I think found the answer to my chronology conundrum. I found that it was D. Martin Dakin's Sherlockian book where I had read about the October date for the Orontes troopship in A Study in Scarlet. Strange that the Annotated Sherlock Holmes didn't make a note about it at all, though it quotes from Dakin about other stuff. Dakin describes the previous research on the ship by Percy Metcalfe, and he cited a "Sherlock Holmes Journal" article as the source. But of course, that was from decades ago and I despaired of being able to buy an obscure SHJ article anywhere online. They do sometimes show up on Ebay, but the "Baker Street Journal" issues are far more widely available.
Just when I was despairing of ever locating it, I found a 2 volume book called The Grand Game: a celebration of Sherlockian Scholarship edited by Laurie R. King and Leslie Klinger. It basically gathers together lots of different Sherlockian essays from several decades, and I was able to see Metcalfe's article listed in the table of contents. The 2011 book was published by the Baker Street Irregulars, but their website listed it as sold out. I searched some rare bookshop sites trying to find a secondhand copy to buy, but it was nowhere. I began to despair again, until I found the book on OpenLibrary, where I could create an account and "borrow" the book so I could read the digital copy. Hooray!
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