One more comment regarding this 861 movement.
It has been previously noted that the lozenge adjustment index is the type found on earlier 321 movements. Of further interest is what appears to be the lack of a screw anchor hole under this index. This is screw anchor hole is normally found in all 861 movements (using MWO as a reference) and should (if it is actually there) be visible under the sides of the 321 index. Opinions?
Also of note, it appears that there are no service markings in either the inside caseback or the underside of the anti magnetic cap.