Sorry to say, but - due to what features are present, and the nuances of several non-matching finish colors, I think that is a very nicely-rendered assembly of parts. Glad you are having fun shooting it.
The stock could go either way, but it is crucial that there not be a step in the inletting at the barrel-receiver joint. With no cartouche, that is one of two ways to tell if the stock is an early or late short-wrist. The other is to pull the trigger guard (VERY carefully) to see if there is a ramrod cleanout hole - there should not be.
The two horizontal bars on the hammer are, I believe, not original. The hammer, thumblatch, and block are the very earliest versions of each, and all were long gone by 71xxx. Early hammers and lockplates (but not blocks) were used on the "star" rebuilds of the early 1880s.
The rear sight has been up-dated from the expected 1873 stepped version, but that is almost a given, so really not a big deal.