there was a place called "The Screw Shop" in Concord Calif.
IIRC you could Google it
They would carry any size & types of specialty screws, washers, nuts, bolts, studs, titanium, stainless, moly, zinc coated, black hardened, in grade 3 to grade 12, dzus fasteners & various tabs etc., 4 pt., 6pt. - 12 pt., undersized or safety wire drilled heads &/or most any fastener related automotive or aircraft rated hardware & if they didn't have it, they would get it for you too, very reasonable priced, it's been years since I was there, but they were the best....
might be worth a trip, to the east-bay, if you need a bunch of stuff,
they may have a mil order service or website now too, I didn't see one...
Fastenal is a great source too
good luck