Dillion Reloaders (http://www.dillonprecision.com/) puts out a catalog called the Blue Press, and the March 2015 issue has a nice article about Spencer Carbines used in the early 1870's. You can download a copy of the catalog at their website.
My copy of the Dillon Blue Press came in the mail and I was elated at reading a new story about Spencer carbines used in the Indian Wars. Also interesting was the story of how Old Mr. Dillon bought his from a local saloon that had to close due to prohibition. The Burnside Spencer's seem to be cheaper, in similar condition to Original Civil War Spencer's on some of the online gun sites.
And the very fine Spencer Shooting Society get a very nice mention in that article!!
;D