Funny you should mention British slang books. I have one I bought years ago, but I doubt this would be in it. I actually bought it to write a book about an episode in American history (still in the planning stages after 30 years) which was close enough to the Revolution that I thought it would be relevant!
Slang is a language form that changes very rapidly, and so these web-based dictionaries are oftentimes quite a bit more up to date than a published book. Some sites update more frequently than others, so when searching for a term check another site or two if you don't find what you're looking for at first.
I actually bought it to write a book about an episode in American history (still in the planning stages after 30 years) which was close enough to the Revolution that I thought it would be relevant!
I'm hoping that you'll soon get beyond the planning stages of this work that you speak of, as your contributions online have always been engaging, insightful and welcome, and I'm guessing that a more studious effort of yours would be quite well received by publishers and readers alike.. :-)
Regarding slang terms as well as mainstream words accepted in polite society around the time of the Revolutionary War, you may possibly find the Oxford English Dictionary to be of some slight help, as word origins and variations going back hundred of years or more are commonly discussed. Be sure to look in the "full" (17 or so volumes) version found at better libraries, as the 2-volume abridged versions will likely be missing precisely what you're looking for.