Not period.
1920s Campaign Hat device.
There are a 'lot' of faked 7th Cavalry items out there - far more than you can conceive of.
A true device from the time frame will be much larger, hollow-backed, and will feature a wire back, encased in solder - sometimes with a pin, sometimes with wire loops for sewing,
The numerals and letters will be separate - not attached - that came later, and when they were attached, it was often by small loops or onto a small brass bar, and as mentioned - that came later - closer to the end of the Indian Wars.
Being of rather flimsy construction, they were often filled in with soft solder for strengthening by the Company Artificer or Blacksmith.
Same's true for Infantry.
The anti-rotation pins and screwbacks came about around the time of the Spanish-American War - for use on the Bell Crowns, and the Campaign Hats of the time - those devices were gilt-finished, as is the one pictured.
Vaya,
Scouts Out!