I look at big picture questions, like:
- What is the gunsmith's purpose? - filling a high demand need for masses of frontiersmen heading out into indian country on the Wilderness Trail? Or building fancy rifles during a time of peace in a safe, coastal part of northern states?
- What was the era? 1776 and 1812 had wars and Indians. 1830 not so much.
- Was the region known widely for gun making, with lots of gunsmiths like the NC Jamestown School? They had dozens of prolific gunsmiths, all making rifles for the trade. You can find dozens of Lamb rifles from there, for example.
It's all about survival rate. If a SW Virginia gunsmith made 10 rifles each winter, and Lamb made 100 a year, you will find more of the latter. Not every gunsmith was making them fast to sell to everyone lined up at the door. Some made fewer, but higher quality. Some made mostly basic rifles, but once in a blue moon made one fancy one.
To SPgordon's point - I would say many, if not MOST frontier gunsmiths were part time makers. That is documented many places, even in Census records, where a known gunsmith often said "Farmer" when asked by the taker what was his occupation. Lancaster or Salem, NC were not the frontier. They were more "Guild societies" where one person did only one thing...all day every day. On the frontier the blacksmith might make guns some too...or fix plows.