There's a lot wrong with that post.
Why on earth is 1969 the technological cut off point/ Why be on the internet- old dead guys sure didn't.
There are a ton of rusted, clapped out old guns- more than pristine for sure- using old school rustproofing is iffy, and certainly can't be relied on for long term storage. Pristine old guns are the exception, not the rule. A product like BC's Barricade is better than any of the old school stuff.
The common mention of "freshing out" barrels seems telling.
The dead old guys didn't have/use brushes or cleaning patches- they used tow. There is also a lot of thought that they didn't use water a lot of the time- just heavy coats of lard or some type of free animal fat.
Bear, whale oil, lard, bees wax pale in comparison to some of the modern lubes.
It's nice to romanticize, but nothing we do today is really like the old days. With the exception of a handfull of builders none of the guns are quite the same. Most builders are a using assemblages of parts. Modern lighting and Stanley Surform files certainly weren't available, neither were screws, drill bits etc, and how many builders are using pump or bow drills etc?