Refinished for sure, and not by a "factory" or arsenal - the receiver and frame show extensive rounding of what should be sharp edges- which is how/why there are no markings.
The serial number on the front of the frame is nearly "polished" away.
The fine tune rear sight continued to show up even into 1918, and perhaps 1/4 to 1/2 of the 1917 dated artilleries had a fine tune front sight- with or without a fine tune rear.
The fine tuning was quite likely eliminated due to cost/time saving efforts, and the fact that after the original sighting in when produced- the sights would not likely have need adjusting thereafter.
After all, the ammo assigned for their military use did not change- not like we swap around sources today. JMHO
