Hi and welcome Wingshot,
You came to the right place. American long rifles before the end of the Rev War generally were of calibers larger than 45, strongly influenced by European styling, primarily Germanic, stocked in maple and mounted with brass hardware. Carving was usually present although often simple. The vast majority of rifles at the time were made in southern PA, western MD, and northern VA. After the war, the rifles tended toward smaller caliber, thinner and lighter stocks, and decoration often included carving and metal inlays. Rifle making also moved along with human migrations into KY, OH, and TN. Rifles mounted with forged iron parts became more popular as did calibers less than 45. Eventually, carved decoration diminished greatly even on "fancy" rifles and was replaced by metal inlays or nothing at all. The small caliber "squirrel" gun you describe is a product of the 19th century, probably the 1830s and later. It would have a good imported lock (not something like a Siler but like Chambers late Ketland) and possibly forged, not cast, iron mounts. The stock likely would be maple or walnut. Shumay's "Rifles in Colonial America" is a good source for early and Rev War period guns. I am sure others can offer some good titles on Southern and Mid-western rifles.
dave