If you wish your writing to be in fine trim when using language of the 1800's and not sound like a puzzle-text, check out The 1811 Dictionary of the Vulgar Tongue: Buckish Slang, University Wit, and Pickpocket Eloquence. I am not tweaking your nose when I say this book can help you add some flavor to your riff raff. Just be careful that your writing cronies don't nip the book from your possession. Make them get their own copy. If necessary, you can find it on Project Guttenberg.
So roll the bones and take a chance to have some fun with vulgar language. Put your characters in a pickle with some rogues. You'll discover naming jokes authors have used such as Fflewddur Fflam's name in the Prydain Chronicles. (Flam is a lie or sham story.) And some words may surprise you with their familiarity. I used a few in this post, can you find them all?
(Puzzle-text - an ignorant blundering parson)