Nat Stein started as an Overland driver in 1861 and eventually advanced to vice president of the company. C Smith appears to have been some sort of station manager in charge of at least three stage stations here. Sometime in the 1880's, there was a "John Allen & Company" here in Helena involved in mining, but I don't know if it would be the same John Allen mentioned by C Smith in his letter some twenty years prior in 1865.
Helena had its beginnings with a gold strike in 1864. The Colt was plowed up in a field ~10 miles east of "Last Chance Gulch" where the gold strike was. Helena's main street is named Last Chance Gulch to this day, and is built right atop the course of the strike.
I can't even hazard a guess as to the significance of C Smith's date of April 29, 1861, nor can I guess when, or how, it may have been lost. C Smith may have met his end at the hands of Indians along the trail to old Fort Benton (the revolver was found maybe a hundred yards off the old trail), or it may have been lost accidentally on a trip to early day Helena. Who knows? Fascinating stuff, this history.
Sometimes the squeaky wheel gets replaced...