CardShopMap lists 26 vintage shops in California. They are spread across 22 cities, including Sacramento (3), Palm Desert (2), and San Jose (2). Of those listings, 12 publish opening hours and 6 are tagged as buying cards. Beyond vintage, they also carry comics (19), Pokémon (17), and sports cards (14).
Every listing links an official website and all of them carry a phone number. 14 listings publish no opening hours at all, so call those before you drive over.
Sacramento carries the most, with 3 listed shops.
The listings carrying the most detail are A-1 Comics Sacramento at 5361 Auburn Blvd in Sacramento, Dhampire at 319 East Market Street in San Diego, and Teddy Bear Square at 583 Pine Knot Ave in Big Bear Lake.
Compare every card shop listed in California