I am attempting to reinvigorate this thread, hoping it will become the repository of discussion of the JP Danielson company, tools, etc, during the time before it was absorbed into the Proto Empire.
Here's my first contribution: a table showing six phases (by color) of the adjustable wrench, from the early 1930s to the early 1960s. The design changes (hard borders) of four features narrow the production date down to approximate decades. Once done, the three-digit date code, Letter-Number-Number (LNN) can be used to determine specific year of production. The rightmost number is the last digit of the year. The central number is believed to represent the month, because it apparently runs from 1 to 12. The letter probably represents the day of production. All known examples run from A to Y, so 25 characters. I have some ideas about this, which I will share in a separate post.
As you can see, sometimes using a single design feature - like the broached hole on these two wrenches - the single digit year can be understood; in the first case, 1940. However, you have to see that the letter form of the second one is sans serif (plain) to distinguish it as 1944, from 1934, which would have a slab serif (typewriter) letterform. The third one is...
That’s right, 1952, because the round hole has no reinforcement.
The fourth case shows the reinforced hole, so...1964.