Both Brant Selb and Don Stith sell Hawken "Squirrel Rifles," in calibers from .32 to .50, I believe. Mr. Selb produces finished rifles, but I think Mr. Stith only sells parts sets. A lot of people get Hawken parts sets from Mr. Stith and send them to a professional builder for assembly. These are nice-looking rifles. The original Hawken shop is known to have made them for the local trade. These are pretty much scaled-down versions of the familiar Hawken plains or mountain rifles, but they generally only have one barrel key, and the trigger guard bow has a finger rest or hook. I believe the Hawken squirrel rifles shown on the Brant Selb website have poured nosecaps.
Sorry, but I haven't mastered the device I'm using right now and can't post links. You can Google "brant selb hawken" or "don stith hawken" to find their websites. Select "Squirrel Rifle" from their drop-down menus.
It should be mentioned that these are top quality rifles, on a par with Mr. Selb's full-sized Hawkens, and they are priced accordingly. "Smaller" does not mean "cheaper." However, these look like historically correct and well-designed rifles.
Good luck!
Notchy Bob