1965 Formula S (with A/C) Ballast Resistor Location?

dibbons said
I found two holes directly behind the power brake booster and two screws in a sandwich bag with a note (I made the note almost 3 years ago) they belong behind the power booster on the firewall. There is no notation whether the two holes or screws serve any purpose.

photo of screw behind p/b booster (one installed/one missing):

Edit: The vacant hole (that is made with a dimple) that is next to the fastener in the photo is for a plastic firewall nail to secure the insulation pad on the inside of firewall.