Jim
One way to answer some hardware questions is to first find a GM# in the 69 assy manual, it should be there if installed by Chevrolet ( not so much on Fisher body installed items)
Then cross the # over on AMK's catalog. There is a great PDF file on there WWW.
This will work most of the time, but having re; info from original cars is great too. The VR screws have a flat tip and are bright. The cowl relay screw I would bet is bright plated based on the finish on the relay, just not sure, AMK offers it bright and phosphate.
AMK PDF catalog
Voltage regulator screws
Do you have these on the wire gutter ? Loose captured washer and several head markings, AMK has these as well.
