How would this work? Yes Wilton date stamps their vises but the same model has dates over several years. The Rock Islands and possibly the Stanleys have their dates stamped. Give me your thoughts.
As you have pointed out some of the vises such as Wilton, RI, Stanley have direct date indicators. But also there are many vises such as Parker, Reed etc that have patent dates. While for the latter category the date will not be exact we can give a range of 20 years from patent date, so a 1930 Parker 974 will have 1930-1950 date range, A 1910 Reed 204 will have a date range of 1910-1930.
To reflect the fact that some of these dates are exact and some are ranges and estimates, we could have one more column that might have Date Status such as
Exact (say RI, Wilton etc)
Good Estimate (vises with patent dates and 20 year range)
Fair Estimate (see below)
Best Guess (see below)
The harder cases are those of many of the vises and brands that do not have any direct indications of date.
But sometimes there are features such as say meatball vs flat nose, oil hole vs no oil hole, or even lack of a patent date and company history to give an indirect date range. For example a Parker 974 with no 1930 Pat date most likely was made between 1950 (1930 patent expiration) and 1957 (when Parker was acquired by Union), similarly a Union Parker was most likely made between 1957 to mid 60s. These later categories can be classified as
Fair Estimate
Best Guess
With the amazing amount of knowledge of the members here it might be possible based on features as well as company history to give such ranges.
Here is another example, last year I saw a vise made by Walworth (a company that I had never heard of). I found an old post on GJ
https://www.garagejournal.com/forum/archive/index.php/t-229201.html
stating that this company went out of business over 100 years ago, well that already gave me a good idea for the min age of the vise and that was very valuable.
Will we get the date for all or even most of the vises? The answer is mostly likely no, but for those that we can (even if it is only something in the ball park) personally I believe there is value to the information. This is my two cents and others might agree or disagree.