This collection of Western stamps is correct but lacking in accuracy/completeness.
Part of the problem is that the stamps used on their folders and fixed blades were sometimes the same and at other times different during the same time frame. Take stamp 1-4. It actually specifies different time frames for folders and fixed blades. BUT, even there it is wrong. Just look at the OP's knife's stamp. Colorado is spelled out. The chart shows that it was "COLO."
Edit - I have been informed that KABAR never made this model for themselves, so the info I had that they made them for Western would be incorrect.
Does that mean that the OP knife is an earlier KABAR knife, a latter Western made version, maybe 1932 to 1941, since the chart says only until 1931? That's one of the frustrating things about "fixing a date" to specific stamps. Sometimes you can be really precise to the year of manufacture and at others, it is simply a black hole.
Stamp 2-1 indicates that the Patent number stamp goes from 1935 to 1950. The patent was for the double tang construction, easily identifiable by the double pins in the pommels of Western fixed blade until Camillus took over manufacture of Western knives. Camillus dropped the DT construction when they bought the name in 1992.
The patent was applied for in 1931. It was "pending" in 1932-1933. It was issued in 1933.
1931-early 1932 knives have "Pat Appl'd For" on them.
Late 1932 - early 1933 knives have "Pat Pending".
From late 1933 until "some point in time", most likely 1934, "Patented" was used until the actual patent number was added.
The chart says that stamp was used until 1950. Harvey Platts, CEO of Western, in his 1977
The Knife Makers Who Went West, says that the reference to the patent number was dropped in 1952.
BUT, he also says that model numbers were first stamped into the blades in 1955, but I have a couple of Westerns with BOTH patent number and model number. Confusing, it is. That's just a couple of issues I have with the chart.
And, as with any "rule of thumb", there are exceptions - The "PAT'D" and "Patented" stamps rear their heads again at some point during WW2 on the G46-8s They were 2 of the multiple stamps used on the knife. And no one has been able to figure out when or why or what order they were used on the G46-8.