Finding a local/regional parts store that is completely independent, with paper books under the counter (OR on the counter!), is getting harder and harder to do. Most of those operators are well past retirement age, typically, and ready to let somebody else have it. Some are still around and do a BIG business, but their ranks are thinning. Most of the counterpeople might know something about cars, but have learned to follow the menus of the computer system. Not unlike the dealers parts people that have been trained to ask for a VIN before they look for anything. As things progress, "product knowledge" is in the computer rather than in the head of the person behind the counter, unfortunately.
Another issue is that while there might be some regional parts store groups, MANY of them can be owned by the same parent company, which is also their supplier. The brands these local stores sell are what the supplier sells, which can change every so often when "a better deal" might come along. NAPA might have the best mix of OEM-level brands/suppliers, although some of the national chains have some good stuff, too. SO, shop for the best deals on parts and those that sell them to you! Amazon, Jeg's, and Summit might be attractive, but not everybody is situated close to one of the Jeg's or Summit stores ("candy stores" for car people).
Personally, I'll use RockAuto to do research to see what's "out there", price and such, then see if there's anybody locally that might have what I desire. Back in the middle '80s, when our Mopar club was young and sponsored by an energetic Dodge parts department, when many 1-800 Chrysler dealers were dealing in Mopar Perf parts, I'd tell people that they were usually better to know what they needed (from the MP catalog), letting the local dealer order it, so that if it was wrong or otherwise, they had a local contact they could "strangle", if needed, rather than holler into the telephone as the person on the other end laid the handset down. Knowing what you really needed was very important, though!
In more current times, though, the person on the other end of the 1-800 line should know more about what you have and how it works than anybody else. PLUS (hopefully) vastly superior product knowledge than anybody locally, I suspect.
Back in the middle '70s, I wanted a "timing tape" to put on the balancer of the '66 Newport. I went to a performance-oriented auto supply store and asked for one. The Younger-than-me guy brought me a timing chain. When I further explained what I wanted, he had to go ask.
Then there was the time I was looking for "ignition point grease". Back in the later '80s when that little vial was missing from any set of ignition points. One guy brought me some "grease", but not THAT grease I('d asked for. One more "I'll have to ask", with the final stop being at SuperShops for that huge tube of Mallory Point Lube they had hanging on the wall.
Frustrations have been around for as long as cars have been on the road, with respect to buying parts for them. Old or new, no matter what.
Enjoy!
CBODY67