Hereswhat it probably is.
I have a reprint of the Sears and Roebuck catalog of 1900.
Item number 34380 "the imported automatic double action revolver, imitation of Smith&Wesson".
(by automatic they meant automatic ejection when opened)
"it has rebounding hammer. rubber stock,weighs 35 ounces and is automatic shell ejecting"
"This revolver takes the same cartridge as the Winchester rifle (no.35409) so that a man who has a 44-40 caliber rifle can use the same ammunition in both the rifle and the revolver."
no.34380 in nickel finish $5.50
no.34381 in blued finish $5.90
(self leveling nickel requiring less polishing than bluing and hiding imperfections)
Those countries that used a .44 revolver prefered the straight cased .44 Russian or .44 S&W due to the tapered case of the .44-40 sometimes tying up the cylinder.
Privately purchased revolvers were not that uncommon among European and Asian officers. Its possible the pistol may have been a war trophy, but without provenance that can't be proven.
The Japanese used some top break S&W revolvers, mostly used by Naval officers of WW1 or earlier. IIRC these were in .44 Russian.
Russia also used the S&W topbreaks in .44 Russian to some extent.