] But I'm wondering what it meant to have a younger son a Merchant Taylors in 1800 or thereabouts.

I hope this is not going too far off topic, but here is a link to the school website, which has history of the school, including an account from a pupil of that time. I would love to know if JA had a connection with Merchant Taylor's School. It was a so-called "Public" school, but not in the premier league of places such as Eton and Westminster. It may have been looked down on by some people because of its connections to "trade" (via the Merchant Taylors) rather than the aristocracy, a bit like Oundle School, which was founded by the Company of Grocers.