I would think that the caveats of dating issues is pretty well understood from car collecting (and bike collecting). Model years and actual date of manufacture can vary significantly. IMO, date codes and serial numbers can pin down model years, not actual date of manufacture in the strictest of senses. A Buck marked with a 1990 date is is a 1990 Buck. Beyond that, people will need to define exactly where in the process the knife was considered "manufactured". When it passed QA inspection and placed in its packaging? When it was recorded and completed inventory? When it was shipped? I personally don't find those questions helpful or interesting. It's a 1990 Buck (model year) and that's enough for me.
In terms of materials use, I find knives trickier than vintage bikes. With bikes, the practice (was) to clearly label the kind of steel used in the frame (it matters as much to cyclists and blade steel does to knife enthusiasts). Lacking clear marking, the only thing that matters to me is documented published specifications from the manufacturer, or other written evidence. This cuts both ways. The fact that Buck changed to 420HC for the 110 in a certain year implies but does not, by itself, establish that Buck switched other models the same year. For me, I would like to see catalogs or other such documentation. Raleigh of England was notorious (in the 70s) for switching frame materials in the middle of production runs due to shortages. Schrade, it seems, had a similar low regard to sticking with published specification. When I look at an old Buck (or any other vintage item), I feel safer saying "The specification for this knife was...." compared to "This knife is....". With written records, I can feel confident about the first. I would need to be a metallurgist to say the second.