I live in Fairfield, CA (Budweiser& JellyBelly).
Nearby is Vacaville and Pacific Hardware.
The store has been owned by the same family for 100+ years.
It started in the small town of Monticello which now lies under Lake Berryessa.
They have EVERY screw, nut, washer, nail ever made.
They are affiliated with ACE hardware and the family owns the ACE store in Suisun outside Travis AFB.
They have screws for all firearms, foreign & domestic as well as scope screws, too
If they don’t have it they will tell you where to get it.