I have a book somewhere on prose in the 19th century that includes a lot of excerpts from Charles Dickens, Jane Austen, and George Eliot (Mary Ann Evans). I can't remember the name of it, but it has a red cover. If your goal is the form of speaking, you may want to focus on some books that go into depth on the structure and include examples. I'm not sure if that's valuable, as I don't train models on my own, but I know that I've had excellent results when I've fed similar things to models and asked them to emulate the style when rewriting something.

As an example, I fed the above reply into Gemini 2.5 with instructions to emulate a number of writers from the 19th/20th century. It's a bit wordy, but I think that's part of the fun of earlier writing. It's less hurried. Here's the response I received:

Ah, a delightful quandary that, alas, echoes through the venerable halls of my own memory! There resides, within the shadowy recesses of my library – though its precise whereabouts, like a phantom in a fog, elude my present grasp – a most edifying tome. Its cover, a vibrant crimson, yet its title, a perplexing void! This cherished volume, if memory serves, dedicates its pages to the exquisite prose of the nineteenth century, replete with excerpts from the likes of Charles Dickens, whose words dance with the very spirit of London's streets; the perspicacious Jane Austen, who weaves narratives with the delicate threads of social grace; and the profound George Eliot, known to the world by her true appellation, Mary Ann Evans, whose insights penetrate the very soul of humanity.

Should your noble endeavor be the very essence of locution, the refined art of expression, then permit me to offer a humble, albeit unconfirmed, counsel. One might do well to seek out those scholarly tomes that delve with profound earnestness into the very architecture of language, dissecting its intricate components and illuminating them with a plethora of illustrative examples. Whether such a pursuit holds true utility for your particular modus operandi – for I, alas, do not personally engage in the arcane craft of model training – remains a matter of conjecture. Yet, I confess, my own humble experiments have yielded truly extraordinary results when such meticulously structured and stylistically rich materials have been presented to these burgeoning intelligences, instructing them to imbue their nascent expressions with a similar literary grandeur. A fascinating prospect, indeed!