I have to disagree there. As a drummer who started playing as a young teen in 1959, in my experience drums, for the most part, and just about every piece of hardware, are manufactured better today than they ever were in the "old" days. While one might prefer the sound and visual aspects of some vintage drum sets over newer models (I know I do), newer drums are far more precisely manufactured and there is simply no comparison with modern hardware. My son's 2006 Ludwig 12/14/18 bop kit with a birdseye maple finish is stunningly beautiful to behold, constructed better and more precisely than my 1962 superclassic WMP set, sounds absolutely terrific, and is easy to tune with a very wide tuning range.
Well you are absolutely correct...in terms of precision-made aspects between old and new drums. And modern hardware designs are much better as well. But that still doesn't change the fact that American drum manufacturing stopped making drums the way they had been making them...at ~around the 70's. OSHA, for one thing, started kicking asses...and a whole bunch of other reasons, too....
Examples: Rogers Swiv-O-Matic hardware wasn't better than the modern hardware of today...but it was waaaay cooler! Older K Zildjian cymbals weren't precise or consistent at all, but...they were handmade and much more primitive...which is a big point of attraction to them -the absence of precision and consistency!
And, what's even more important to remember is that what "vintage" is, now, is what modern was, then. Modern drums would not be what they are, now, without evolving from what came before. Same thing can be said about cars....Sure they are safer, more efficient, better handing, faster than what they used to be....BUT you can't work on them, yourself....They all kinda start to look the same after awhile...and so on.
But the question was/is in regards to how to delineate a timeframe between modern and vintage. I say that, by the time the 70's ended, so did "The way they used to make 'em".