Remember as well, the 1884 was a fatigue uniform, basicily a plain canvas oversuit for stable cleaning. But the troops liked it so much, especialy in hotter climates, that it was quickly modified for field use. Enlisted simply sewed on some stripes, but officers had much more elaborate modification done, such as a stand up collar and branch cuffs.
But none of this was by regulation, so the uniforms vary somewhat from unit to unit, or even different individuals. Photos show officer 1884s with full stand up collars, short stand ups with unhooked rounded down fronts, or unmodified fold over collars. Gold buttons, black buttons, and mixtures of the two. Most have strap rank, some have added sewn on epulats. All are acceptable.