My high school band toured the Chicago Ludwig plant in 1976. I was 15 at the time. Based on that experience and what I saw I think you'd have been very hard pressed to find a single worker below management status that really "gave a Sh!t" about the fit and finish of the drums. It was a dirty, noisy environment where hundreds of folks went about their day doing their single task over and over again. In other words, a factory. If you didn't know they were making drums you could have easily been persuaded that they were turning out furniture, frying pans, or engine blocks. So they were regular people from the neighborhood, happy to have a job and a paycheck, but spending each day eyeing the clock waiting for quitting time to roll around. In other words, typical factory workers. I'm sure there were some there who honestly wanted to do the best they could, but they were mostly doing repetitive tasks for an eight hour shift and that wears anyone down eventually. If you spend eight hours a day feeding dowels into a drumstick lathe (incredibly noisy and the sound of multiple lathes reverberated throughout the place) or screwing lugs onto a shell, or operating a drill press you will eventually become numbed to the task.
I mention this, not to disparage Ludwig, or the workers, I love the products they were churning out, imperfections and all, but to inject a dose of reality. It was a factory environment and it operated as such. I know many have romanticized notions of men in white lab coats, each carefully constructing a drum from scratch one at a time, but that was not the way it was done, at Ludwig, or at any of the major drum makers back then. At the time this level of quality was good enough for, if not every customer, perhaps, at least the vast majority of them. In the era before clear heads it might be years before a drum owner saw the interior of one of his drums. When he did it was doubtful that he paid that much attention unless something truly jarring was apparent. We just, for the most part, accepted what we were sold and as long as it worked we were happy.
Trends in drum sounds also played a part in this. In the 50's and 60s the close up sound didn't matter anywhere outside a recording studio. In a concert setting the drummer was bashing on them just to be heard. In the 70's when live close miking became more common the single head sound was in vogue as was a dead tom sound and drummers were even spending money on add-on gadgets to kill as much resonance as possible. If a drum was slightly out of round or had a badly cut bearing edge it might just mean the drummer needed a bit less duct tape to achieve his desired sound.
None of this would fly today and the drum companies, with much smaller workforces and much fussier clientele, have addressed most of these issues in the past 30 years or so. Even the very cheapest First Act drums have shells that are built to a higher standard than the top of the line drums of 60 years ago (and yet still don't sound as good....hmmm?). But we can't honestly expect the drums from 50 or 60 years ago to live up to the standards of today...but they did meet the standards of their day, which was, admittedly, a much lower threshold to cross.
Vintage drums are great (I have LOT of them) but they come with certain peccadillos that are to be anticipated (maybe embraced) and, if you expect the sort of perfection that those imaginary men in white coats might have achieved, you are bound to end up with some level of disappointment. But if you can tolerate these usually minor quirks you can be rewarded with great sounding drums that have some history and "mojo" behind them.