Thanks John, I sorta assumed, whether valid or not, that the Z28 master cylinder was intended for a JL-8, since the part number I described calls for "ALL 69 front disc Camaros except Z28".
I confirmed no check valve (RPV), by using the blunt end of a 7/64th drill bit, I should probably consider installing one before using this master cylinder.
The 69 Chasis Service Manual makes a strong emphasis on the correct secondary piston. Short of disassembling the main cylinder, is it safe to assume that I have the correct secondary piston installed? Are the aftermarket or replacement pistons marked or grooved correctly as the originals for identification?