Hatted eff:
Your original post question makes me wonder what makes one guitar "better" than another?
(And I'm not trying to be a wise ankle.)
I can pick up two or sometimes more "identical" guitars in a music store and one sounds better to me. That would be the one I would buy, saying it was better than the others.
You might pick and purchase a different one from the same group as sounding better to you.
So I think that particular notion of better (sound quality) is difficult to quantify.
Do we mean simply build quality when we say "better". No sharp fret ends, no finish flaws, clean glue joints at the internal braces, no gaps in the binding. Those things can be quantified and are related to the quality standards and the quality control measures in place by a particular manufacturer or owner.
Then we have the quality of the woods, which can be interpreted as mainly visual - straight quarter-sawn grain - no knots - no grain runout in the top, or as material properties such as density, stiffness, hardness, etc. I'm sure folks could argue all day about how the visual aspects of the woods do or do not effect the tonal quality, and the same for the wood material properties.
If a guitar really astounded me with great tone, but the frets ends were sharp, would I say it was not a great guitar, or would I say it was a great guitar that needed some work?
I just wonder if it ever makes sense to generalize and say that such and such guitars from a certain time frame or certain corporate owner were better, without defining what better means. Maybe the design was changed to use less wood, a different bracing pattern, a thinner finish, or otherewise take costs out of manufacturing. If we don't know the specifics of construction, I just think it is difficult to generalize about better guitars from certain eras.
I have a Tacoma D-55 from 2007. Someone else has a Westerly D-55. Mine looks better because it is new. His sounds better but has finish checks and a chunk missing from the headstock. Which is the better guitar? If they both sound the same, which is the better guitar?
I think we lump all or many of these things together when we speak of a "better" guitar, and that can make things very subjective, and discussions about better building eras cloudy.