Anthony, your Harness Jack came from an interesting company. Most of my info comes from books by Bernie Levine, John and Charlotte Goins, and Phil Pankiewicz.
George and William Miller decided to manufacture cutlery at the end of the Civil War. As gunsmiths, they were well trained in using tool steel. They opened a cutlery in 1863, and grew and moved twice, in 1870, and in 1872, winding up in Meriden CT. Like many early knifemakers their business ran into trouble and was reorganized in 1878. Under better business management it flourished until 1926 as a cutlery.
Noted for good quality, they made knives that often used screws to anchor the handle material, which allowed it to be easily changed if broken in manufacturing, or in use.
The punch on your knife was invented by Seymour Alvord, the second generation Alvord to run Empire Knife Co.
S. Alvord received a patent for the punch in 1906, and it was used in many other brands contracted by Empire. Its widespread use was probably because it was very effective, and relatively staightforward to manufacture. I don't know if Miller Bros. made them under license, or bought them already ground from Empire, to use in their knives.. Someday I will get a few punches out of knives and see if the way the tangs are made sheds some light on that. If anyone who collects documents knows anything, please let me know.
A cluster of punch patents were issued from 1902 to 1918, 9 different ones that I know of. This reflects the importance of horses in society during that time period, and hence the demand for punches to care for the various types of Harness used.
Hope this info is interesting for all. In the era of the Harness Jack, I imagine that everyone who had or worked with a horse carried some kind of harness knife. A simple jack was the least expensive one that would get the job done. A rich man would of course own a full-on horseman's knife with all the tools including a corkscrew!! I like the humble ones myself.
Respectfully submitted,
Charlie C.