Swinney's work has about four pages on Stuart. He made nicely finished, mostly plain, typical half-stock mid 19th century rifles.
To my knowledge no one other than Swinney has ever written on New York State rifles. Ned Roberts covers a few, but not Stewart.
I would be curious to know, should you ever remove the barrel, if there is a barrel maker's name, such as Losey, underneath. Your rifle probably has a steel, rather than wrought iron barrel. In NY the more prominant barrel suppliers were Remington, and Lull & Losey.
Me, I'm trying to finish the 2nd Edition of Michigan Gunsmiths, all I know about NY is what J. Holman Swinney wrote. & what a couple of Losey descendants have told me. Michigan was heavily influenced by New York and New England styles, maybe 1/3 of our gun makers came from New York.