You suppose the guys issued Double action Starr Revolvers during the American Civil War thought it was an amazing advancement or thought it an over-complicated, overweight version of the Colt Percussions of the day. . .
This one was later converted to fire a 44 cal Centerfire round (Russian?) I was able to find 2 main veins of conversions on these, ones that often have european proofs (IE Converted for that market), and this style that seems a more American style Conversion and very well done, similar to how many percussion revolvers were converted in the latter half of the 1800s.
Excerpt from one with an identical conversion:
“Civil War Star Arms Model 1858 Double Action Army revolver, which sometime after the war was converted to take centerfire brass cartridges. It is marked with serial number of 10875 under the hammer and on the barrel frame, indicating production in mid 1862. This revolver was part of a production run of around 21,500 revolvers, delivered to the U.S. Army 1862-1863. After this, starting at serial number 23,000, they moved to the requested Single Action Model of 1863, which cost HALF of what the earlier model did. The conversion to center fire was definitely done either at arsenal, or by a skilled gunsmith. This was definitely not some basement job. The cylinder was either turned down from a percussion cylinder and bored out, or possibly could be entirely new manufacture. A circular metal plate has been attached directly to the recoil shield, and has a spring loaded firing pin installed, which is actuated by the hammer.”