LOL... funny you should post this about the Old Timers....
I am trying to figure out how to get my hands on a few stragglers for my collection...
Year model and tang stamp isn't a great concern of mine.... Just as long as it says "USA
" on it.... LOL.
It's a slippery slope when it comes to tang stamps. The older the knife is dated from the tang stamp makes it more desirable for some collectors. THEN, you have to look at the condition of the blades. Factory fresh.... sharpened once.... heavily sharpened.... sharpened to a nub... All these factors go into the collect-ability (and VALUE) of a knife.
I have seen people put knives out for sale that have the old tang stamps but they blades are practically gone.... LOL.... If you ask they are quick to tell you, "This is an old one and really valuable."
Anyway, I guess to put it in a nutshell, the tang stamp does give you an age range for the time period it was made.