How does one go about finding the value of one of these rifles in original condition?

Were you ever able to find a knowledgeable site, person that was helpful with this?
Finding one in that condition seems almost too good to be true.

Go to Trapdoor collector.com and look in the catalog section under 1865-1893 arms and compare to the condition of the rifles offered and the asking price. The postings are accurate and the prices reasonable.