Kelsey Hayes setup lower ball joint to spindle bolts

I'm wondering if anyone knows a source for the round headed bolts that attach the lower ball joints to the spindles on A-bodies with the Kelsey Hayes disc setup. Australian made Valiants use something that looks the same but we don't have a source that's a reasonable price locally.
65-72 A Body Disc Brakes #5 017 (Copy).JPG